Dear Editor,This letter presents a latent-factorization-of-tensors(LFT)-incorporated battery cycle life prediction framework.Data-driven prognosis and health management(PHM)for battery pack(BP)can boost the safety and...Dear Editor,This letter presents a latent-factorization-of-tensors(LFT)-incorporated battery cycle life prediction framework.Data-driven prognosis and health management(PHM)for battery pack(BP)can boost the safety and sustainability of a battery management system(BMS),which relies heavily on the quality of the measured BP data like the voltage(V),current(I),and temperature(T).展开更多
Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from...Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from the cathode side.These challenges lead to poor cycle stability and severe self-discharge.From the fabrication and cost point of view,it is technologically more viable to deploy electrolyte engineering than electrode protection strategies.More importantly,a synchronous method for modulation of both cathode and anode is pivotal,which has been often neglected in prior studies.In this work,cationic poly(allylamine hydrochloride)(Pah^(+))is adopted as a low-cost dual-function electrolyte additive for ZIBs.We elaborate the synchronous effect by Pah^(+)in stabilizing Zn anode and immobilizing polyiodide anions.The fabricated Zn-iodine coin cell with Pah^(+)(ZnI_(2) loading:25 mg cm^(−2))stably cycles 1000 times at 1 C,and a single-layered 3.4 cm^(2) pouch cell(N/P ratio~1.5)with the same mass loading cycles over 300 times with insignificant capacity decay.展开更多
Rapid evolutions of the Internet of Electric Vehicles(IoEVs)are reshaping and modernizing transport systems,yet challenges remain in energy efficiency,better battery aging,and grid stability.Typical charging methods a...Rapid evolutions of the Internet of Electric Vehicles(IoEVs)are reshaping and modernizing transport systems,yet challenges remain in energy efficiency,better battery aging,and grid stability.Typical charging methods allow for EVs to be charged without thought being given to the condition of the battery or the grid demand,thus increasing energy costs and battery aging.This study proposes a smart charging station with an AI-powered Battery Management System(BMS),developed and simulated in MATLAB/Simulink,to increase optimality in energy flow,battery health,and impractical scheduling within the IoEV environment.The system operates through real-time communication,load scheduling based on priorities,and adaptive charging based on batterymathematically computed State of Charge(SOC),State of Health(SOH),and thermal state,with bidirectional power flow(V2G),thus allowing EVs’participation towards grid stabilization.Simulation results revealed that the proposed model can reduce peak grid load by 37.8%;charging efficiency is enhanced by 92.6%;battery temperature lessened by 4.4℃;SOH extended over 100 cycles by 6.5%,if compared against the conventional technique.By this way,charging time was decreased by 12.4% and energy costs dropped by more than 20%.These results showed that smart charging with intelligent BMS can boost greatly the operational efficiency and sustainability of the IoEV ecosystem.展开更多
The operation of deep-sea underwater vehicles relies entirely on onboard batteries.However,the extreme deep-sea conditions,characterized by ultrahigh hydraulic pressure,low temperature,and seawater conductivity,pose s...The operation of deep-sea underwater vehicles relies entirely on onboard batteries.However,the extreme deep-sea conditions,characterized by ultrahigh hydraulic pressure,low temperature,and seawater conductivity,pose significant challenges for battery development.These conditions drive the need for specialized designs in deep-sea batteries,incorporating critical aspects of power generation,protection,distribution,and management.Over time,deep-sea battery technology has evolved through multiple generations,with lithium(Li)batteries emerging in recent decades as the preferred power source due to their high energy and reduced operational risks.Although the rapid progress of Li batteries has notably advanced the capabilities of underwater vehicles,critical technical issues remain unresolved.This review first systematically presents the whole picture of deep-sea battery manufacturing,focusing on Li batteries as the current mainstream solution for underwater power.It examines the key aspects of deep-sea Li battery development,including materials selection informed by electro-chemo-mechanics models,component modification and testing,and battery management systems specialized in software and hardware.Finally,it discusses the main challenges limiting the utilization of deep-sea batteries and outlines promising directions for future development.Based on the systematic reflection on deep-sea batteries and discussion on deep-sea Li batteries,this review aims to provide a research foundation for developing underwater power tailored for extreme environmental exploration.展开更多
Single-atom catalysts(SACs)have garnered significant attention in lithium-sulfur(Li-S)batteries for their potential to mitigate the severe polysulfide shuttle effect and sluggish redox kinetics.However,the development...Single-atom catalysts(SACs)have garnered significant attention in lithium-sulfur(Li-S)batteries for their potential to mitigate the severe polysulfide shuttle effect and sluggish redox kinetics.However,the development of highly efficient SACs and a comprehensive understanding of their structure-activity relationships remain enormously challenging.Herein,a novel kind of Fe-based SAC featuring an asymmetric FeN_(5)-TeN_(4) coordination structure was precisely designed by introducing Te atom adjacent to the Fe active center to enhance the catalytic activity.Theoretical calculations reveal that the neighboring Te atom modulates the local coordination environment of the central Fe site,elevating the d-band center closer to the Fermi level and strengthening the d-p orbital hybridization between the catalyst and sulfur species,thereby immobilizing polysulfides and improving the bidirectional catalysis of Li-S redox.Consequently,the Fe-Te atom pair catalyst endows Li-S batteries with exceptional rate performance,achieving a high specific capacity of 735 mAh g^(−1) at 5 C,and remarkable cycling stability with a low decay rate of 0.038%per cycle over 1000 cycles at 1 C.This work provides fundamental insights into the electronic structure modulation of SACs and establishes a clear correlation between precisely engineered atomic configurations and their enhanced catalytic performance in Li-S electrochemistry.展开更多
Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electro...Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electrocatalytic reaction kinetics at the cathode.The integration of light energy into Zn/Sn-air batteries is a promising strategy for enhancing their performance.However,the photothermal and photoelectric effects generate heat in the battery under prolonged solar irradiation,leading to air cathode instability.This paper presents the first design and synthesis of Ni_(2)-1,5-diamino-4,8-dihydroxyanthraquinone(Ni_(2)DDA),an electronically conductiveπ-d conjugated metal-organic framework(MOF).Ni_(2)DDA exhibits both photoelectric and photothermal effects,with an optical band gap of~1.14 eV.Under illumination,Ni_(2)DDA achieves excellent oxygen evolution reaction performance(with an overpotential of 245 mV vs.reversible hydrogen electrode at 10 mA cm^(−2))and photothermal stability.These properties result from the synergy between the photoelectric and photothermal effects of Ni_(2)DDA.Upon integration into Zn/Sn-air batteries,Ni_(2)DDA ensures excellent cycling stability under light and exhibits remarkable performance in high-temperature environments up to 80℃.This study experimentally confirms the stable operation of photo-assisted Zn/Sn-air batteries under high-temperature conditions for the first time and provides novel insights into the application of electronically conductive MOFs in photoelectrocatalysis and photothermal catalysis.展开更多
Na-ion batteries are considered a promising next-generation battery alternative to Li-ion batteries,due to the abundant Na resources and low cost.Most efforts focus on developing new materials to enhance energy densit...Na-ion batteries are considered a promising next-generation battery alternative to Li-ion batteries,due to the abundant Na resources and low cost.Most efforts focus on developing new materials to enhance energy density and electrochemical performance to enable it comparable to Li-ion batteries,without considering thermal hazard of Na-ion batteries and comparison with Li-ion batteries.To address this issue,our work comprehensively compares commercial prismatic lithium iron phosphate(LFP) battery,lithium nickel cobalt manganese oxide(NCM523) battery and Na-ion battery of the same size from thermal hazard perspective using Accelerating Rate Calorimeter.The thermal hazard of the three cells is then qualitatively assessed from thermal stability,early warning and thermal runaway severity perspectives by integrating eight characteristic parameters.The Na-ion cell displays comparable thermal stability with LFP while LFP exhibits the lowest thermal runaway hazard and severity.However,the Na-ion cell displays the lowest safety venting temperature and the longest time interval between safety venting and thermal runaway,allowing the generated gas to be released as early as possible and detected in a timely manner,providing sufficient time for early warning.Finally,a database of thermal runaway characteristic temperature for Li-ion and Na-ion cells is collected and processed to delineate four thermal hazard levels for quantitative assessment.Overall,LFP cells exhibit the lowest thermal hazard,followed by the Na-ion cells and NCM523 cells.This work clarifies the thermal hazard discrepancy between the Na-ion cell and prevalent Li-ion cells,providing crucial guidance for development and application of Na-ion cell.展开更多
Exploration budgets for primary battery metals-nickel,lithium and cobalt-tempered in 2024 at$1.697 billion,reflecting a marginal 0.4%decline and a virtually flat annual total,compared to$1.704 billion in 2023.Below is...Exploration budgets for primary battery metals-nickel,lithium and cobalt-tempered in 2024 at$1.697 billion,reflecting a marginal 0.4%decline and a virtually flat annual total,compared to$1.704 billion in 2023.Below is an introduction to the 2024 global exploration trends and prospects for lithium,cobalt,and nickel battery metals.展开更多
Accurate State-of-Health(SOH)prediction is critical for the safe and efficient operation of lithium-ion batteries(LiBs).However,conventional methods struggle with the highly nonlinear electrochemical dynamics and decl...Accurate State-of-Health(SOH)prediction is critical for the safe and efficient operation of lithium-ion batteries(LiBs).However,conventional methods struggle with the highly nonlinear electrochemical dynamics and declining accuracy over long-horizon forecasting.To address these limitations,this study proposes CIPF-Informer,a novel digital twin framework that integrates the Informer architecture with Channel Independence(CI)and a Particle Filter(PF).The CI mechanism enhances robustness by decoupling multivariate state dependencies,while the PF captures the complex stochastic variations missed by purely deterministic models.The proposed framework was evaluated using the Massachusetts Institute of Technology(MIT)battery dataset against benchmark deep learning models.Results demonstrate that CIPF-Informer consistently achieves superior performance,in multivariate and long sequence forecasting scenarios.By effectively synergizing a model-based method with a data-driven model,CIPF-Informer provides a more reliable pathway for advancing Battery Management System(BMS)technologies,contributing to the development of safer and more sustainable energy storage systems.展开更多
The use of lithium-ion batteries(LIBs)-operated underground mining machinery has gained tremendous momentum as a result of their numerous advantages.This includes their high energy density,long cycle life,high voltage...The use of lithium-ion batteries(LIBs)-operated underground mining machinery has gained tremendous momentum as a result of their numerous advantages.This includes their high energy density,long cycle life,high voltage delivery,low heat release,stability,negligible memory efects,and low carbon footprint.Battery operated vehicles are also preferred in underground mines for their fexibility.They do not emit harmful pollutants during nominal operations,making the work environment safer for miners.However,thermal runaway(TR)incidents can occur which presents risks to miners and underground infrastructure.Therefore,it is crucial to understand battery operations and their failure mechanisms.This article outlines the advantages of LIBs,the necessary precautions for their safe operations underground,the conditions and impact of TR events,battery management systems,handling LIB fre emergencies,and the research opportunities to promote safer and widespread use.展开更多
The implementation of the standard is expected to help electric vehicle battery swap stations to adapt to diversified needs and vehicle models,promoting the industry’s orderly and healthy development.
In this work,a flexible battery structure is fabricated using soft lithography and three-dimensional(3D) printing technology.Ga_(52.5)Sn_(39.5)Zn_(8) anode material,Bi_(67)In_(33) cathode material,and alkaline hydroge...In this work,a flexible battery structure is fabricated using soft lithography and three-dimensional(3D) printing technology.Ga_(52.5)Sn_(39.5)Zn_(8) anode material,Bi_(67)In_(33) cathode material,and alkaline hydrogel electrolyte are introduced to form the flexible battery.A variety of circuit structures are fabricated to realize the series-parallel integration of different numbers of single cells and achieve the fabrication of batteries with different voltages and powers,with a maximum open-circuit voltage(OCV) of 4.6 V and a maximum output power of 1.193 mW.A reconfigurable soft battery group is proposed,and the regulation of the battery voltage has been realized through the microfluidic perfusion process without the need for an external variable-voltage circuit.We have also fabricated an EGaIn-NaOH microfluidic switch to achieve the control of the light emitting diode(LED).In addition,a wristband with a flexible battery is demonstrated to realize power supply to a liquid crystal display(LCD) with a clock or a temperature sensor.展开更多
As battery deployments in electric vehicles and energy storage systems grow, ensuring homogeneous performance across units is crucial. We propose a multi-derivative imaging fusion(MDIF) model, employing advanced imagi...As battery deployments in electric vehicles and energy storage systems grow, ensuring homogeneous performance across units is crucial. We propose a multi-derivative imaging fusion(MDIF) model, employing advanced imaging and machine learning to predict battery aging trajectories from minimal initial data, thus facilitating effective performance grouping before deployment. Utilizing a derivative strategy and Gramian Angular Difference Field for dimensional enhancement, the MDIF model uncovers subtle predictive features from discharge curve data after only ten cycles. The architecture includes a parallel convolutional neural network with lateral connections to enhance feature integration and extraction.Tested on a self-developed dataset, the model achieves an average root-mean-square error of 0.047 Ah and an average mean absolute percentage error of 1.60%, demonstrating high precision and reliability.Its robustness is further validated through transfer learning on two publicly available datasets, adapting with minimal retraining. This approach significantly reduces the testing cycles required, lowering both time and costs associated with battery testing. By enabling precise battery behavior predictions with limited data, the MDIF model optimizes battery utilization and deployment strategies, enhancing system efficiency and sustainability.展开更多
Lithium-ion batteries(LIBs)are widely used in electrochemical battery energy storage systems(BESS)because of their high energy density,lack of memory effects,low self-discharge rate,and long cycle life.However,inadequ...Lithium-ion batteries(LIBs)are widely used in electrochemical battery energy storage systems(BESS)because of their high energy density,lack of memory effects,low self-discharge rate,and long cycle life.However,inadequate heat dissipation during their discharge process can significantly degrade battery performance.The improvement of BESS efficiency depends on the optimization of thermal management structures.In this work,we integrate the pseudo-two-dimensional(P2D)electrochemical model with a three-dimensional thermal model to analyze the heat generation and transfer processes within the BESS.The simulation results are closely aligned with the experimental results in terms of voltage and temperature rise curves.Under air cooling conditions of 293.15 K and 3 m·s^(-1),the BESS has a maximum temperature of 308.60 K and a temperature difference of 9.22 K,ensuring safe operation.At 1 C,we suggest that enlarging the inlet and outlet areas improves the air-cooling efficiency,and transitioning environmental air-cooling temperatures after 2400 s of discharge effectively reduces the temperature difference and the energy consumption of the cooling equipment.This work provides valuable theoretical insights for optimizing the thermal design of BESS.展开更多
Accurate state of health(SOH)estimation is a cornerstone for ensuring the safety,performance and longevity of lithium-ion batteries,especially in electric vehicle(EV)applications.While numerous studies have demonstrat...Accurate state of health(SOH)estimation is a cornerstone for ensuring the safety,performance and longevity of lithium-ion batteries,especially in electric vehicle(EV)applications.While numerous studies have demonstrated the significant advantages of data-driven methods in SOH estimation,most rely on laboratory-standardized test data.This raises concerns about the generalization and robustness of the models under real-world operating conditions,where batteries undergo irregular driving patterns,incomplete charging cycles,and unpredictable environments.Notably,real-world EV data reflects the coupling between battery aging characteristics and actual operating conditions,providing an unprecedented perspective for developing SOH estimation models.This review provides a comprehensive and systematic overview of data-driven SOH estimation using real-world data,a topic that has received increasing attention but lacks a consolidated research framework.The paper begins by reviewing the established SOH estimation methodologies and points out the specific challenges arising from the transition to real-world data.It then probes practical issues across the pipeline:data pre-processing for anomalies,solutions for the lack of labels,feature extraction from complex operating data,machine learning model construction,and performance evaluation across various system deployments.Key insights are presented on how to handle noisy,unlabeled,and heterogeneous data using robust modeling strategies.Moreover,a valuable extension focusing on applying the advancements to battery reuse and recycling is discussed,with the goal of developing a whole lifecycle health diagnosis framework.The paper concludes with promising prospects,encompassing open-source standardized dataset establishment,weakly supervised learning,physics-reinforced modeling,real-world deployment,and advanced sensing technology,emphasizing that real-world data makes the transition of data-driven methods from theoretical validation to industrial deployment promising.This paper aims to assist researchers and practitioners in navigating the complexities of real-world SOH estimation,accelerating the collaborative innovation and industrial adoption in battery health management.展开更多
Aqueous hybrid-ion batteries(AHBs)are a promising class of energy storage devices characterized by low cost,high safety,and high energy density.However,aqueous Cu-Al hybrid-ion batteries face challenges such as sluggi...Aqueous hybrid-ion batteries(AHBs)are a promising class of energy storage devices characterized by low cost,high safety,and high energy density.However,aqueous Cu-Al hybrid-ion batteries face challenges such as sluggish reaction kinetics and severe structural collapse of cathode materials,which limit their practical application.Here,a high-performance aqueous Cu-Al hybrid-ion battery is developed using aluminum pre-inserted Cu_(9)S_(5)(Al-Cu_(9)S_(5))as the cathode material,derived from CuAl-layered double hydroxide(CuAl-LDH).The Al^(3+)pre-intercalation strategy narrows the band gap,enhancing electron transport and improving electrochemical kinetics.The battery exhibits excellent rate performance(463 and 408 mA h g^(-1)at current densities of 500 and 1000 mA g^(-1),respectively)and good cycle stability(with a capacity retention ratio of 81% after 300 cycles at a current density of 1000 mA g^(-1)).Its performance surpasses that of most reported Al-ion batteries.Ex situ characterization and density functional theory(DFT)calculations reveal that the pre-intercalated Al^(3+)in Al-Cu9S5participates in the reversible embedding/removal of Al ions during charge/discharge processes.These findings provide valuable insights for designing pre-intercalated cathodes in aqueous Cu-Al hybrid-ion batteries with stable cycle life.展开更多
Flexible Zn-based batteries have attracted increasing research interest as essential components of wearable energy storage devices.However,the advancement of flexible aqueous Zn-based batteries based on Co-Ni layered ...Flexible Zn-based batteries have attracted increasing research interest as essential components of wearable energy storage devices.However,the advancement of flexible aqueous Zn-based batteries based on Co-Ni layered double hydroxide (CoNi-LDH) as the cathode material is hampered by their poor cycling stability and the corrosiveness of alkaline electrolytes.Herein,CoNi-LDH nanosheets enriched with H vacancies (CoNi-LDH(v)) were constructed on a flexible carbon cloth (CC) substrate via electrochemical deposition and activation.The Zn-based battery comprising CoNi-LDH(v)@CC as the cathode exhibited highly reversible conversion reactions and stable operation in 3 M ZnSO4electrolyte (pH=4).The battery delivered an excellent specific capacity (225 mA h g^(-1),0.26 mA h cm^(-2)),acceptable cycling stability(53.9%,900 cycles),and high discharging voltage.The abundant H vacancies served as active sites for the reversible intercalation of Zn^(2+)and the extravasation of NO_(3)-generated channels and space for Zn^(2+)transport and storage,together enabling an excellent Zn^(2+)storage capacity.Furthermore,a sandwich-structured solid-state CoNi-LDH(v)@CC//Zn@CC battery was fabricated and was found to exhibit a noteworthy electrochemical performance and mechanical durability.As a proof of concept,the unencapsulated battery powered a digital watch under various deformation conditions and operated stably for 80 h.Additionally,the flexible battery displayed outstanding customizability,maintaining an open-circuit voltage of 1.42 V even after being cut twice.The proposed engineering strategy contributes to the realization of textiles with truly wearable energy-storage devices.展开更多
Lithium-carbon dioxide(Li-CO_(2))batteries using high ion-conductive inorganic molten salt electrolytes have recently attracted much attention due to the high energy density and potential application of carbon neutral...Lithium-carbon dioxide(Li-CO_(2))batteries using high ion-conductive inorganic molten salt electrolytes have recently attracted much attention due to the high energy density and potential application of carbon neutrality.However,the poor Li-ion conductivity of the molten-salt electrolytes at room temperature(RT)makes these batteries lose most of their capacity and power as the temperature falls below 80℃.Here,inspired by the greenhouse effect,we report an RT molten salt Li-CO_(2)battery where solar energy can be efficiently harvested and converted into heat that is further localized on the cathode consisting of plasmonic ruthenium(Ru)catalysts and Li_(2)CO_(3)-based products via a greenhouse-like phenomenon.As a result,the solar-driven molten salt Li-CO_(2)battery demonstrates a larger full discharge/charge capacity of 9.5 mA h/8.1 mA h,and a longer cycle lifespan of 250 cycles at 500 mA/g with a limited capacity of 500 mA h/g at RT than the molten salt Li-CO_(2)battery at 130℃.Notably,the average temperature of the cathode increases by 8℃ after discharge to 0.75 mA h,which indicates the infrared radiation from Ru catalysts can be effectively suppressed by discharged Li_(2)CO_(3)-based products.This battery technology paves the way for developing low-temperature molten salt energy storage devices.展开更多
The increasing penetration of second-life battery energy storage systems(SLBESS)in power grids presents substantial challenges to system operation and control due to the heterogeneous characteristics and uncertain deg...The increasing penetration of second-life battery energy storage systems(SLBESS)in power grids presents substantial challenges to system operation and control due to the heterogeneous characteristics and uncertain degradation patterns of repurposed batteries.This paper presents a novel model-free adaptive voltage controlembedded dung beetle-inspired heuristic optimization algorithmfor optimal SLBESS capacity configuration and power dispatch.To simultaneously address the computational complexity and ensure system stability,this paper develops a comprehensive bilevel optimization framework.At the upper level,a dung beetle optimization algorithmdetermines the optimal SLBESS capacity configuration byminimizing total lifecycle costswhile incorporating the charging/discharging power trajectories derived from the model-free adaptive voltage control strategy.At the lower level,a health-priority power dispatch optimization model intelligently allocates power demands among heterogeneous battery groups based on their real-time operational states,state-of-health variations,and degradation constraints.The proposed model-free approach circumvents the need for complex battery charging/discharging power controlmodels and extensive historical data requirements whilemaintaining system stability through adaptive controlmechanisms.A novel cycle life degradation model is developed to quantify the relationship between remaining useful life,depth of discharge,and operational patterns.The integrated framework enables simultaneous strategic planning and operational control,ensuring both economic efficiency and extended battery lifespan.The effectiveness of the proposed method is validated through comprehensive case studies on hybrid energy storage systems,demonstrating superior computational efficiency,robust performance across different network configurations,and significant improvements in battery utilization compared to conventional approaches.展开更多
A sustainable approach for recovering battery grade FePO_(4) and Li_(2)CO_(3) from Al/F-bearing spent LiFePO_(4)/C powder was proposed,including acid leaching,fluorinated coordination precipitation,homogeneous precipi...A sustainable approach for recovering battery grade FePO_(4) and Li_(2)CO_(3) from Al/F-bearing spent LiFePO_(4)/C powder was proposed,including acid leaching,fluorinated coordination precipitation,homogeneous precipitation,and high-temperature precipitation.Under the optimal conditions,the leaching efficiencies of Li,Fe,P,Al,and F were 97.6%,97.1%,97.1%,72.5%,and 63.3%,respectively.The effects of different parameters on the removal of Al/F impurities were systematically evaluated,indicating about 99.4%Al and 96.4%F in the leachate were precipitated in the form of Na_(3)Li_(3)Al_(2)F_(12),and their residual concentrations were only 0.0124 and 0.328 g/L,respectively,which could be directly used to prepare battery grade FePO_(4)(99.68%in purity).Lithium in the Al/F-bearing residue could be extracted through CaCO_(3)−CaSO_(4) roasting followed by acid leaching,ultimately obtaining 99.87%purity of Li_(2)CO_(3).The recovery rates of Li and Fe were 96.88%and 92.85%,respectively.An economic evaluation demonstrated that the process was profitable.展开更多
文摘Dear Editor,This letter presents a latent-factorization-of-tensors(LFT)-incorporated battery cycle life prediction framework.Data-driven prognosis and health management(PHM)for battery pack(BP)can boost the safety and sustainability of a battery management system(BMS),which relies heavily on the quality of the measured BP data like the voltage(V),current(I),and temperature(T).
基金supported by the financial support from the National Research Foundation,Singapore,under its Singapore-China Joint Flagship Project(Clean Energy).
文摘Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from the cathode side.These challenges lead to poor cycle stability and severe self-discharge.From the fabrication and cost point of view,it is technologically more viable to deploy electrolyte engineering than electrode protection strategies.More importantly,a synchronous method for modulation of both cathode and anode is pivotal,which has been often neglected in prior studies.In this work,cationic poly(allylamine hydrochloride)(Pah^(+))is adopted as a low-cost dual-function electrolyte additive for ZIBs.We elaborate the synchronous effect by Pah^(+)in stabilizing Zn anode and immobilizing polyiodide anions.The fabricated Zn-iodine coin cell with Pah^(+)(ZnI_(2) loading:25 mg cm^(−2))stably cycles 1000 times at 1 C,and a single-layered 3.4 cm^(2) pouch cell(N/P ratio~1.5)with the same mass loading cycles over 300 times with insignificant capacity decay.
文摘Rapid evolutions of the Internet of Electric Vehicles(IoEVs)are reshaping and modernizing transport systems,yet challenges remain in energy efficiency,better battery aging,and grid stability.Typical charging methods allow for EVs to be charged without thought being given to the condition of the battery or the grid demand,thus increasing energy costs and battery aging.This study proposes a smart charging station with an AI-powered Battery Management System(BMS),developed and simulated in MATLAB/Simulink,to increase optimality in energy flow,battery health,and impractical scheduling within the IoEV environment.The system operates through real-time communication,load scheduling based on priorities,and adaptive charging based on batterymathematically computed State of Charge(SOC),State of Health(SOH),and thermal state,with bidirectional power flow(V2G),thus allowing EVs’participation towards grid stabilization.Simulation results revealed that the proposed model can reduce peak grid load by 37.8%;charging efficiency is enhanced by 92.6%;battery temperature lessened by 4.4℃;SOH extended over 100 cycles by 6.5%,if compared against the conventional technique.By this way,charging time was decreased by 12.4% and energy costs dropped by more than 20%.These results showed that smart charging with intelligent BMS can boost greatly the operational efficiency and sustainability of the IoEV ecosystem.
基金support provided by National Key Research and Development Program of China(2023YFE0203000 and 2016YFC0300200)the NSAF(Grant No.U2330205)+3 种基金Full-Sea-Depth Battery Project(2020-XXXX-XX-246-00)Open project of Shaanxi Laboratory of Aerospace Power(2022ZY2-JCYJ-01-09)Fundamental Research Funds for the Central Universities,ND Basic Research Funds(G2022WD)the Innovation Team of Shaanxi Province。
文摘The operation of deep-sea underwater vehicles relies entirely on onboard batteries.However,the extreme deep-sea conditions,characterized by ultrahigh hydraulic pressure,low temperature,and seawater conductivity,pose significant challenges for battery development.These conditions drive the need for specialized designs in deep-sea batteries,incorporating critical aspects of power generation,protection,distribution,and management.Over time,deep-sea battery technology has evolved through multiple generations,with lithium(Li)batteries emerging in recent decades as the preferred power source due to their high energy and reduced operational risks.Although the rapid progress of Li batteries has notably advanced the capabilities of underwater vehicles,critical technical issues remain unresolved.This review first systematically presents the whole picture of deep-sea battery manufacturing,focusing on Li batteries as the current mainstream solution for underwater power.It examines the key aspects of deep-sea Li battery development,including materials selection informed by electro-chemo-mechanics models,component modification and testing,and battery management systems specialized in software and hardware.Finally,it discusses the main challenges limiting the utilization of deep-sea batteries and outlines promising directions for future development.Based on the systematic reflection on deep-sea batteries and discussion on deep-sea Li batteries,this review aims to provide a research foundation for developing underwater power tailored for extreme environmental exploration.
基金supported by the National Natural Science Foundation(52302284,22002086,22204096)Shanghai Sailing Program(23YF1412200)the Fundamental Research Funds for the Central Universities(22120240314).
文摘Single-atom catalysts(SACs)have garnered significant attention in lithium-sulfur(Li-S)batteries for their potential to mitigate the severe polysulfide shuttle effect and sluggish redox kinetics.However,the development of highly efficient SACs and a comprehensive understanding of their structure-activity relationships remain enormously challenging.Herein,a novel kind of Fe-based SAC featuring an asymmetric FeN_(5)-TeN_(4) coordination structure was precisely designed by introducing Te atom adjacent to the Fe active center to enhance the catalytic activity.Theoretical calculations reveal that the neighboring Te atom modulates the local coordination environment of the central Fe site,elevating the d-band center closer to the Fermi level and strengthening the d-p orbital hybridization between the catalyst and sulfur species,thereby immobilizing polysulfides and improving the bidirectional catalysis of Li-S redox.Consequently,the Fe-Te atom pair catalyst endows Li-S batteries with exceptional rate performance,achieving a high specific capacity of 735 mAh g^(−1) at 5 C,and remarkable cycling stability with a low decay rate of 0.038%per cycle over 1000 cycles at 1 C.This work provides fundamental insights into the electronic structure modulation of SACs and establishes a clear correlation between precisely engineered atomic configurations and their enhanced catalytic performance in Li-S electrochemistry.
基金supported by the National Natural Science Foundation of China(No.62464010)Spring City Plan-Special Program for Young Talents(K202005007)+2 种基金Yunnan Talents Support Plan for Young Talents(XDYC-QNRC-2022-0482)Yunnan Local Colleges Applied Basic Research Projects(202101BA070001-138)Frontier Research Team of Kunming University 2023.
文摘Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electrocatalytic reaction kinetics at the cathode.The integration of light energy into Zn/Sn-air batteries is a promising strategy for enhancing their performance.However,the photothermal and photoelectric effects generate heat in the battery under prolonged solar irradiation,leading to air cathode instability.This paper presents the first design and synthesis of Ni_(2)-1,5-diamino-4,8-dihydroxyanthraquinone(Ni_(2)DDA),an electronically conductiveπ-d conjugated metal-organic framework(MOF).Ni_(2)DDA exhibits both photoelectric and photothermal effects,with an optical band gap of~1.14 eV.Under illumination,Ni_(2)DDA achieves excellent oxygen evolution reaction performance(with an overpotential of 245 mV vs.reversible hydrogen electrode at 10 mA cm^(−2))and photothermal stability.These properties result from the synergy between the photoelectric and photothermal effects of Ni_(2)DDA.Upon integration into Zn/Sn-air batteries,Ni_(2)DDA ensures excellent cycling stability under light and exhibits remarkable performance in high-temperature environments up to 80℃.This study experimentally confirms the stable operation of photo-assisted Zn/Sn-air batteries under high-temperature conditions for the first time and provides novel insights into the application of electronically conductive MOFs in photoelectrocatalysis and photothermal catalysis.
基金supported by the National Key R&D Program of China(No.2022YFE0207400)supported by the Xiaomi Young Talents Programsupported by the Youth Innovation Promotion Association CAS(No.Y201768)。
文摘Na-ion batteries are considered a promising next-generation battery alternative to Li-ion batteries,due to the abundant Na resources and low cost.Most efforts focus on developing new materials to enhance energy density and electrochemical performance to enable it comparable to Li-ion batteries,without considering thermal hazard of Na-ion batteries and comparison with Li-ion batteries.To address this issue,our work comprehensively compares commercial prismatic lithium iron phosphate(LFP) battery,lithium nickel cobalt manganese oxide(NCM523) battery and Na-ion battery of the same size from thermal hazard perspective using Accelerating Rate Calorimeter.The thermal hazard of the three cells is then qualitatively assessed from thermal stability,early warning and thermal runaway severity perspectives by integrating eight characteristic parameters.The Na-ion cell displays comparable thermal stability with LFP while LFP exhibits the lowest thermal runaway hazard and severity.However,the Na-ion cell displays the lowest safety venting temperature and the longest time interval between safety venting and thermal runaway,allowing the generated gas to be released as early as possible and detected in a timely manner,providing sufficient time for early warning.Finally,a database of thermal runaway characteristic temperature for Li-ion and Na-ion cells is collected and processed to delineate four thermal hazard levels for quantitative assessment.Overall,LFP cells exhibit the lowest thermal hazard,followed by the Na-ion cells and NCM523 cells.This work clarifies the thermal hazard discrepancy between the Na-ion cell and prevalent Li-ion cells,providing crucial guidance for development and application of Na-ion cell.
文摘Exploration budgets for primary battery metals-nickel,lithium and cobalt-tempered in 2024 at$1.697 billion,reflecting a marginal 0.4%decline and a virtually flat annual total,compared to$1.704 billion in 2023.Below is an introduction to the 2024 global exploration trends and prospects for lithium,cobalt,and nickel battery metals.
基金supported by the Human Resources Development of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Korea government Ministry of Knowledge Economy(No.RS-2023-00244330)the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.NRF RS-2023-00219052).
文摘Accurate State-of-Health(SOH)prediction is critical for the safe and efficient operation of lithium-ion batteries(LiBs).However,conventional methods struggle with the highly nonlinear electrochemical dynamics and declining accuracy over long-horizon forecasting.To address these limitations,this study proposes CIPF-Informer,a novel digital twin framework that integrates the Informer architecture with Channel Independence(CI)and a Particle Filter(PF).The CI mechanism enhances robustness by decoupling multivariate state dependencies,while the PF captures the complex stochastic variations missed by purely deterministic models.The proposed framework was evaluated using the Massachusetts Institute of Technology(MIT)battery dataset against benchmark deep learning models.Results demonstrate that CIPF-Informer consistently achieves superior performance,in multivariate and long sequence forecasting scenarios.By effectively synergizing a model-based method with a data-driven model,CIPF-Informer provides a more reliable pathway for advancing Battery Management System(BMS)technologies,contributing to the development of safer and more sustainable energy storage systems.
文摘The use of lithium-ion batteries(LIBs)-operated underground mining machinery has gained tremendous momentum as a result of their numerous advantages.This includes their high energy density,long cycle life,high voltage delivery,low heat release,stability,negligible memory efects,and low carbon footprint.Battery operated vehicles are also preferred in underground mines for their fexibility.They do not emit harmful pollutants during nominal operations,making the work environment safer for miners.However,thermal runaway(TR)incidents can occur which presents risks to miners and underground infrastructure.Therefore,it is crucial to understand battery operations and their failure mechanisms.This article outlines the advantages of LIBs,the necessary precautions for their safe operations underground,the conditions and impact of TR events,battery management systems,handling LIB fre emergencies,and the research opportunities to promote safer and widespread use.
文摘The implementation of the standard is expected to help electric vehicle battery swap stations to adapt to diversified needs and vehicle models,promoting the industry’s orderly and healthy development.
基金supported by the Science and Technology Program from State Grid Corporation of China through the Development of Flexible Liquid Metal Based Micro-Sensor with Anti-Electromagnetic Interference Ability for Power Engineering Applications under Grant 5700-202155453A-00-00。
文摘In this work,a flexible battery structure is fabricated using soft lithography and three-dimensional(3D) printing technology.Ga_(52.5)Sn_(39.5)Zn_(8) anode material,Bi_(67)In_(33) cathode material,and alkaline hydrogel electrolyte are introduced to form the flexible battery.A variety of circuit structures are fabricated to realize the series-parallel integration of different numbers of single cells and achieve the fabrication of batteries with different voltages and powers,with a maximum open-circuit voltage(OCV) of 4.6 V and a maximum output power of 1.193 mW.A reconfigurable soft battery group is proposed,and the regulation of the battery voltage has been realized through the microfluidic perfusion process without the need for an external variable-voltage circuit.We have also fabricated an EGaIn-NaOH microfluidic switch to achieve the control of the light emitting diode(LED).In addition,a wristband with a flexible battery is demonstrated to realize power supply to a liquid crystal display(LCD) with a clock or a temperature sensor.
基金National Natural Science Foundation of China (Grant No. 52225705)。
文摘As battery deployments in electric vehicles and energy storage systems grow, ensuring homogeneous performance across units is crucial. We propose a multi-derivative imaging fusion(MDIF) model, employing advanced imaging and machine learning to predict battery aging trajectories from minimal initial data, thus facilitating effective performance grouping before deployment. Utilizing a derivative strategy and Gramian Angular Difference Field for dimensional enhancement, the MDIF model uncovers subtle predictive features from discharge curve data after only ten cycles. The architecture includes a parallel convolutional neural network with lateral connections to enhance feature integration and extraction.Tested on a self-developed dataset, the model achieves an average root-mean-square error of 0.047 Ah and an average mean absolute percentage error of 1.60%, demonstrating high precision and reliability.Its robustness is further validated through transfer learning on two publicly available datasets, adapting with minimal retraining. This approach significantly reduces the testing cycles required, lowering both time and costs associated with battery testing. By enabling precise battery behavior predictions with limited data, the MDIF model optimizes battery utilization and deployment strategies, enhancing system efficiency and sustainability.
基金sponsored by the National Key Research and Development Program of China(2022YFA1503501)the National Natural Science Foundation of China(22278127,22378112)+1 种基金the Fundamental Research Funds for the Central Universities(2022ZFJH004)21C Innovation Laboratory,Contemporary Amperex Technology Ltd by project No.21C-368 OP-202312,Shanghai Pilot Proaram for Basic Research(22T01400100-18)。
文摘Lithium-ion batteries(LIBs)are widely used in electrochemical battery energy storage systems(BESS)because of their high energy density,lack of memory effects,low self-discharge rate,and long cycle life.However,inadequate heat dissipation during their discharge process can significantly degrade battery performance.The improvement of BESS efficiency depends on the optimization of thermal management structures.In this work,we integrate the pseudo-two-dimensional(P2D)electrochemical model with a three-dimensional thermal model to analyze the heat generation and transfer processes within the BESS.The simulation results are closely aligned with the experimental results in terms of voltage and temperature rise curves.Under air cooling conditions of 293.15 K and 3 m·s^(-1),the BESS has a maximum temperature of 308.60 K and a temperature difference of 9.22 K,ensuring safe operation.At 1 C,we suggest that enlarging the inlet and outlet areas improves the air-cooling efficiency,and transitioning environmental air-cooling temperatures after 2400 s of discharge effectively reduces the temperature difference and the energy consumption of the cooling equipment.This work provides valuable theoretical insights for optimizing the thermal design of BESS.
基金supported by the National Natural Science Foundation of China(52375144 and 52205153)the Shanghai Pujiang Programme(23PJD019)the Shanghai Gaofeng Project for University Academic Program Development。
文摘Accurate state of health(SOH)estimation is a cornerstone for ensuring the safety,performance and longevity of lithium-ion batteries,especially in electric vehicle(EV)applications.While numerous studies have demonstrated the significant advantages of data-driven methods in SOH estimation,most rely on laboratory-standardized test data.This raises concerns about the generalization and robustness of the models under real-world operating conditions,where batteries undergo irregular driving patterns,incomplete charging cycles,and unpredictable environments.Notably,real-world EV data reflects the coupling between battery aging characteristics and actual operating conditions,providing an unprecedented perspective for developing SOH estimation models.This review provides a comprehensive and systematic overview of data-driven SOH estimation using real-world data,a topic that has received increasing attention but lacks a consolidated research framework.The paper begins by reviewing the established SOH estimation methodologies and points out the specific challenges arising from the transition to real-world data.It then probes practical issues across the pipeline:data pre-processing for anomalies,solutions for the lack of labels,feature extraction from complex operating data,machine learning model construction,and performance evaluation across various system deployments.Key insights are presented on how to handle noisy,unlabeled,and heterogeneous data using robust modeling strategies.Moreover,a valuable extension focusing on applying the advancements to battery reuse and recycling is discussed,with the goal of developing a whole lifecycle health diagnosis framework.The paper concludes with promising prospects,encompassing open-source standardized dataset establishment,weakly supervised learning,physics-reinforced modeling,real-world deployment,and advanced sensing technology,emphasizing that real-world data makes the transition of data-driven methods from theoretical validation to industrial deployment promising.This paper aims to assist researchers and practitioners in navigating the complexities of real-world SOH estimation,accelerating the collaborative innovation and industrial adoption in battery health management.
基金supported by the National Natural Science Foundation of China(Nos.22278020 and 2177060378)the Fundamental Research Funds for the Central Universities(Nos.12060093063 and XK1803-05)the Program for Changjiang Scholars and Innovative Research Teams in University(No.IRT1205)。
文摘Aqueous hybrid-ion batteries(AHBs)are a promising class of energy storage devices characterized by low cost,high safety,and high energy density.However,aqueous Cu-Al hybrid-ion batteries face challenges such as sluggish reaction kinetics and severe structural collapse of cathode materials,which limit their practical application.Here,a high-performance aqueous Cu-Al hybrid-ion battery is developed using aluminum pre-inserted Cu_(9)S_(5)(Al-Cu_(9)S_(5))as the cathode material,derived from CuAl-layered double hydroxide(CuAl-LDH).The Al^(3+)pre-intercalation strategy narrows the band gap,enhancing electron transport and improving electrochemical kinetics.The battery exhibits excellent rate performance(463 and 408 mA h g^(-1)at current densities of 500 and 1000 mA g^(-1),respectively)and good cycle stability(with a capacity retention ratio of 81% after 300 cycles at a current density of 1000 mA g^(-1)).Its performance surpasses that of most reported Al-ion batteries.Ex situ characterization and density functional theory(DFT)calculations reveal that the pre-intercalated Al^(3+)in Al-Cu9S5participates in the reversible embedding/removal of Al ions during charge/discharge processes.These findings provide valuable insights for designing pre-intercalated cathodes in aqueous Cu-Al hybrid-ion batteries with stable cycle life.
基金National Natural Science Foundation of China (52003191,5247317, 52473275)Young Elite Scientists Sponsorship Program by CAST (2022QNRC001)+3 种基金Natural Science Foundation of Jiangsu Province (BK20221539)Postgraduate Research&Practice Innovation Program of Jiangsu Province (KYCX22_2341)Program of Introducing Talents of Jiangnan University (1065219032210150)Program of China Scholarship Council (202306790065)。
文摘Flexible Zn-based batteries have attracted increasing research interest as essential components of wearable energy storage devices.However,the advancement of flexible aqueous Zn-based batteries based on Co-Ni layered double hydroxide (CoNi-LDH) as the cathode material is hampered by their poor cycling stability and the corrosiveness of alkaline electrolytes.Herein,CoNi-LDH nanosheets enriched with H vacancies (CoNi-LDH(v)) were constructed on a flexible carbon cloth (CC) substrate via electrochemical deposition and activation.The Zn-based battery comprising CoNi-LDH(v)@CC as the cathode exhibited highly reversible conversion reactions and stable operation in 3 M ZnSO4electrolyte (pH=4).The battery delivered an excellent specific capacity (225 mA h g^(-1),0.26 mA h cm^(-2)),acceptable cycling stability(53.9%,900 cycles),and high discharging voltage.The abundant H vacancies served as active sites for the reversible intercalation of Zn^(2+)and the extravasation of NO_(3)-generated channels and space for Zn^(2+)transport and storage,together enabling an excellent Zn^(2+)storage capacity.Furthermore,a sandwich-structured solid-state CoNi-LDH(v)@CC//Zn@CC battery was fabricated and was found to exhibit a noteworthy electrochemical performance and mechanical durability.As a proof of concept,the unencapsulated battery powered a digital watch under various deformation conditions and operated stably for 80 h.Additionally,the flexible battery displayed outstanding customizability,maintaining an open-circuit voltage of 1.42 V even after being cut twice.The proposed engineering strategy contributes to the realization of textiles with truly wearable energy-storage devices.
基金supported by the National Natural Science Foundation of China(NSFC,62104099,61921005,62105048,62204117 and 62073299)the Science and Technology Research Program of Chongqing Education Commission(KJQN202100633)+5 种基金the Postdoctoral Science Foundation of China(2021M693768 and 2021M701057)the Key Scientific Research Project in Colleges and Universities of Henan Province,China(21A416001)the Key Laboratory for Special Functional Materials(KEKT2022-06)the Natural Science Foundation of Jiangsu Province(BK20210275 and BK20230498)the support from Jiangsu Province Science Foundation for Youths(BK20210275)National Natural Science Foundation of China(NSFC,62204117)。
文摘Lithium-carbon dioxide(Li-CO_(2))batteries using high ion-conductive inorganic molten salt electrolytes have recently attracted much attention due to the high energy density and potential application of carbon neutrality.However,the poor Li-ion conductivity of the molten-salt electrolytes at room temperature(RT)makes these batteries lose most of their capacity and power as the temperature falls below 80℃.Here,inspired by the greenhouse effect,we report an RT molten salt Li-CO_(2)battery where solar energy can be efficiently harvested and converted into heat that is further localized on the cathode consisting of plasmonic ruthenium(Ru)catalysts and Li_(2)CO_(3)-based products via a greenhouse-like phenomenon.As a result,the solar-driven molten salt Li-CO_(2)battery demonstrates a larger full discharge/charge capacity of 9.5 mA h/8.1 mA h,and a longer cycle lifespan of 250 cycles at 500 mA/g with a limited capacity of 500 mA h/g at RT than the molten salt Li-CO_(2)battery at 130℃.Notably,the average temperature of the cathode increases by 8℃ after discharge to 0.75 mA h,which indicates the infrared radiation from Ru catalysts can be effectively suppressed by discharged Li_(2)CO_(3)-based products.This battery technology paves the way for developing low-temperature molten salt energy storage devices.
基金Financial support was provided by the State Grid Sichuan Electric Power Company Science and Technology Project“Key Research on Development Path Planning and Key Operation Technologies of New Rural Electrification Construction”under Grant No.52199623000G.
文摘The increasing penetration of second-life battery energy storage systems(SLBESS)in power grids presents substantial challenges to system operation and control due to the heterogeneous characteristics and uncertain degradation patterns of repurposed batteries.This paper presents a novel model-free adaptive voltage controlembedded dung beetle-inspired heuristic optimization algorithmfor optimal SLBESS capacity configuration and power dispatch.To simultaneously address the computational complexity and ensure system stability,this paper develops a comprehensive bilevel optimization framework.At the upper level,a dung beetle optimization algorithmdetermines the optimal SLBESS capacity configuration byminimizing total lifecycle costswhile incorporating the charging/discharging power trajectories derived from the model-free adaptive voltage control strategy.At the lower level,a health-priority power dispatch optimization model intelligently allocates power demands among heterogeneous battery groups based on their real-time operational states,state-of-health variations,and degradation constraints.The proposed model-free approach circumvents the need for complex battery charging/discharging power controlmodels and extensive historical data requirements whilemaintaining system stability through adaptive controlmechanisms.A novel cycle life degradation model is developed to quantify the relationship between remaining useful life,depth of discharge,and operational patterns.The integrated framework enables simultaneous strategic planning and operational control,ensuring both economic efficiency and extended battery lifespan.The effectiveness of the proposed method is validated through comprehensive case studies on hybrid energy storage systems,demonstrating superior computational efficiency,robust performance across different network configurations,and significant improvements in battery utilization compared to conventional approaches.
基金financially supported by the Key Research and Development Program of Guangxi,China(No.GUIKE AB23026051)the Science and Technology Innovation Program of Hunan Province,China(No.2023RC3039)the Fundamental Research Funds for the Central Universities of Central South University,China.
文摘A sustainable approach for recovering battery grade FePO_(4) and Li_(2)CO_(3) from Al/F-bearing spent LiFePO_(4)/C powder was proposed,including acid leaching,fluorinated coordination precipitation,homogeneous precipitation,and high-temperature precipitation.Under the optimal conditions,the leaching efficiencies of Li,Fe,P,Al,and F were 97.6%,97.1%,97.1%,72.5%,and 63.3%,respectively.The effects of different parameters on the removal of Al/F impurities were systematically evaluated,indicating about 99.4%Al and 96.4%F in the leachate were precipitated in the form of Na_(3)Li_(3)Al_(2)F_(12),and their residual concentrations were only 0.0124 and 0.328 g/L,respectively,which could be directly used to prepare battery grade FePO_(4)(99.68%in purity).Lithium in the Al/F-bearing residue could be extracted through CaCO_(3)−CaSO_(4) roasting followed by acid leaching,ultimately obtaining 99.87%purity of Li_(2)CO_(3).The recovery rates of Li and Fe were 96.88%and 92.85%,respectively.An economic evaluation demonstrated that the process was profitable.
