The efficient recycling of spent lithium iron phosphate(LiFePO_(4),also referred to as LFP)should convert Fe(Ⅱ)to Fe(Ⅲ),which is key to the extraction of Li and separation of Fe and is not well understood.Herein,we ...The efficient recycling of spent lithium iron phosphate(LiFePO_(4),also referred to as LFP)should convert Fe(Ⅱ)to Fe(Ⅲ),which is key to the extraction of Li and separation of Fe and is not well understood.Herein,we systematically study the oxidation of LiFePO_(4)in the air and in the solution containing oxidants such as H_(2)O_(2)and the effect of oxidation on the leaching behaviors of LFP.In the air,O_(2)breaks down the LFP olivine structure at 550℃for 1 h by oxidizing Fe(Ⅱ)to Fe(Ⅲ)in terms of converting LFP to Li_(3)Fe_(2)(PO_(4))_(3)and Fe_(2)O_(3).After that,Li is leached in 0.5 M sulfuric acid solution and is further recycled as Li_(3)PO_(4)with a Li recovery efficiency of 97.48%.Meanwhile,Fe is recovered as FePO_(4)and Fe_(2)O_(3).Compared with H_(2)SO_(4)-H_(2)O_(2),the air oxidation saves H_(2)O_(2)but increases the leaching efficiency of Fe and H_(2)SO_(4)consumption.The discrepancy of Fe leaching efficiency can be attributed to the different leaching mechanisms involving the solid-to-solid and solid-to-liquid-to-solid conversions.Furthermore,the results of the Everbatt model analysis show that the air roasting-H_(2)SO_(4)leaching method has low emission and potentially high income,which is simple and safe.Overall,this work will deepen the understanding of acid leaching of LFP and favorably stimulate the maturation of the LFP recycling technique.展开更多
The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion batteries.Lithium manganese iron phosphate(LiMn_(x)Fe_(1-x)PO_(4))has garnered...The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion batteries.Lithium manganese iron phosphate(LiMn_(x)Fe_(1-x)PO_(4))has garnered significant attention as a promising positive electrode material for lithium-ion batteries due to its advantages of low cost,high safety,long cycle life,high voltage,good high-temperature performance,and high energy density.Although LiMn_(x)Fe_(1-x)PO_(4)has made significant breakthroughs in the past few decades,there are still facing great challenges in poor electronic conductivity and Li-ion diffusion,manganese dissolution affecting battery cycling performance,as well as low tap density.This review systematically summarizes the reaction mechanisms,various synthesis methods,and electrochemical properties of LiMn_(x)Fe_(1-x)PO_(4)to analyze reaction processes accurately and guide material preparation.Later,the main challenges currently faced are concluded,and the corresponding various modification strategies are discussed to enhance the reaction kinetics and electrochemical performance of LiMn_(x)Fe_(1-x)PO_(4),including multi-scale particle regulation,heteroatom doping,surface coating,as well as microscopic morphology design.Finally,in view of the current research challenges faced by intrinsic reaction processes,kinetics,and energy storage applications,the promising research directions are anticipated.More importantly,it is expected to provide key insights into the development of high-performance and stable LiMn_(x)Fe_(1-x)PO_(4)materials,to achieve practical energy storage requirements.展开更多
Iron phosphate based glass-ceramics with deliberately added Ce as an active nuclide simulant were prepared by microwave sintering.The sintering characteristics,including phases and structural evolution,and chemical du...Iron phosphate based glass-ceramics with deliberately added Ce as an active nuclide simulant were prepared by microwave sintering.The sintering characteristics,including phases and structural evolution,and chemical durability were investigated.XRD showed that NaZr_(2)(PO_(4))_(3) and FePO_(4) became the main crystalline phases of glass-ceramics with increasing sintering temperature.SEM revealed the glass-ceramics compactness increased first and then decreased as sintering temperature increased.Raman spectrum showed that,as sintering temperature increased,the network structure of glass-ceramics changed from mainly containing orthophosphate and pyrophosphate to a single orthophosphate.After immersion for 28 days,LR_(Na),LR_(Zr) and LR_(Ce) of the glass-ceramics prepared at 1000℃ were as low as 3.64×10^(-5),0.25×10^(-9) and 5.70×10^(-9)g/m^(2)/d respectively.The results indicate that iron phosphate based glass-ceramics can be prepared by rapid microwave sintering of glass powders and there is a potential of employing such microwave sintering technique in processing of glass-ceramics nuclear waste form.展开更多
Lithium iron phosphate(LFP)has found many applications in the field of electric vehicles and energy storage systems.However,the increasing volume of end-of-life LFP batteries poses an urgent challenge in terms of envi...Lithium iron phosphate(LFP)has found many applications in the field of electric vehicles and energy storage systems.However,the increasing volume of end-of-life LFP batteries poses an urgent challenge in terms of environmental sustainability and resource management.Therefore,the development and implementation of efficient LFP battery recycling methods are crucial to address these challenges.This article presents a novel,comprehensive evaluation framework for comparing different lithium iron phosphate relithiation techniques.The framework includes three main sets of criteria:direct production cost,electrochemical performance,and environmental impact.Each criterion is scored on a scale of 0–100,with higher scores indicating better performance.The direct production cost is rated based on material costs,energy consumption,key equipment costs,process duration and space requirements.Electrochemical performance is assessed by rate capability and cycle stability.Environmental impact is assessed based on CO_(2)emissions.The framework provides a standardized technique for researchers and industry professionals to objectively compare relithiation methods,facilitating the identification of the most promising approaches for further development and scale-up.The total average score across the three criterion groups for electrochemical,chemical,and hydrothermal relithiation methods was approximately 60 points,while sintering scored 39 points,making it the least attractive relithiation technique.Combining approaches outlined in publications with scores exceeding 60,a relithiation scheme was proposed to achieve optimal electrochemical performance with minimal resource consumption and environmental impact.The results demonstrate the framework’s applicability and highlight areas for future research and optimization in lithium iron phosphate cathode recycling.展开更多
With the boom in electric vehicles(EVs),there is an increasing demand for high-performance lithium-ion batteries.Lithium manganese iron phosphate(LMFP)has emerged as an enhanced variation of LiFePO4(LFP),offering an e...With the boom in electric vehicles(EVs),there is an increasing demand for high-performance lithium-ion batteries.Lithium manganese iron phosphate(LMFP)has emerged as an enhanced variation of LiFePO4(LFP),offering an energy density 10%–20%greater than that of LFP.Structural distortion caused by the Jahn–Teller effect decreases the capacity and voltage platform,thus restricting the commercialization of this material.Herein,ideas to overcome these challenges,including the crystal structure of LMFP and strategies to mitigate the Jahn–Teller distortion,are first explored.Then,the migration pathways of Li+during charging and discharging and the phase transition mechanisms that affect the material’s performance are discussed.Next,the optimal Mn:Fe ratio for achieving the desired performance is described.The influences of various synthesis and modification methods on the morphology and structure of LMFP are reviewed.Additionally,different modification techniques,such as doping and coating,to enhance the performance of LMFP are highlighted.Finally,an overview of the current state of research on the recycling and reuse of LMFP is provided.By addressing these key topics,this paper offers a theoretical foundation for the further development of LMFP,thus contributing to its eventual commercialization.展开更多
The effective reuse of iron phosphate residue(IPR)is the key issue in the recycling of spent LiFePO_(4)batteries.Therefore,in this study,the reduction leaching of IPR in H_(2)SO_(4)solution by adding iron powder as re...The effective reuse of iron phosphate residue(IPR)is the key issue in the recycling of spent LiFePO_(4)batteries.Therefore,in this study,the reduction leaching of IPR in H_(2)SO_(4)solution by adding iron powder as reducing agent was investigated and compared with direct leaching.The results show that the leaching rate of IPR reached 97%under the optimum reduction leaching conditions.Kinetic studies show that the activation energy for reduction leaching is 12.71 k J/mol,while that of direct leaching is 21.57 k J/mol.Moreover,the reduction leaching time is reduced by half and the acid consumption is reduced by 30% compared to direct leaching with the same leaching rate.This work provides a scientific guidance to the treatment of iron phosphate residue from the recycling of spent LiFePO_(4)batteries.展开更多
Applying spent lithium iron phosphate battery as raw material,valuable metals in spent lithium ion battery were effectively recovered through separation of active material,selective leaching,and stepwise chemical prec...Applying spent lithium iron phosphate battery as raw material,valuable metals in spent lithium ion battery were effectively recovered through separation of active material,selective leaching,and stepwise chemical precipitation.Using stoichiometric Na2S2O8 as an oxidant and adding low-concentration H2SO4 as a leaching agent was proposed.This route was totally different from the conventional methods of dissolving all of the elements into solution by using excess mineral acid.When experiments were done under optimal conditions(Na2S2O8-to-Li molar ratio 0.45,0.30 mol/L H2SO4,60℃,1.5 h),leaching efficiencies of 97.53% for Li^+,1.39%for Fe^3+,and 2.58% for PO4^3−were recorded.FePO4 was then recovered by a precipitation method from the leachate while maintaining the pH at 2.0.The mother liquor was concentrated and maintained at a temperature of approximately 100℃,and then a saturated sodium carbonate solution was added to precipitate Li2CO3.The lithium recovery yield was close to 80%.展开更多
Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phospha...Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the p K _a values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was not correlated with p K _a. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.展开更多
The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the ...The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the TR hazard severity of LIBs,are not known.In this paper,the TR and gas venting behavior of three 100 A h lithium iron phosphate(LFP)batteries with different safety valves are investigated under overheating.Compared to previous studies,the main contribution of this work is in studying and evaluating the effect of gas venting behavior and TR hazard severity of LFP batteries with three safety valve types.Two significant results are obtained:(Ⅰ)the safety valve type dominates over gas venting pressure of battery during safety venting,the maximum gas venting pressure of LFP batteries with a round safety valve is 3320 Pa,which is one order of magnitude higher than other batteries with oval or cavity safety valve;(Ⅱ)the LFP battery with oval safety valve has the lowest TR hazard as shown by the TR hazard assessment model based on gray-fuzzy analytic hierarchy process.This study reveals the effect of safety valve type on TR and gas venting,providing a clear direction for the safety valve design.展开更多
The recycling of cathode materials from spent lithium-ion battery has attracted extensive attention,but few research have focused on spent blended cathode materials.In reality,the blended materials of lithium iron pho...The recycling of cathode materials from spent lithium-ion battery has attracted extensive attention,but few research have focused on spent blended cathode materials.In reality,the blended materials of lithium iron phosphate and ternary are widely used in electric vehicles,so it is critical to design an effective recycling technique.In this study,an efficient method for recovering Li and Fe from the blended cathode materials of spent LiFePO_(4)and LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)batteries is proposed.First,87%A1 was removed by alkali leaching.Then,91.65%Li,72.08%Ni,64.6%Co and 71.66%Mn were further separated by selective leaching with H_(2)SO_(4)and H_(2)O_(2).Li,Ni,Co and Mn in solution were recovered in the form of Li_(2)CO_(3)and hydroxide respectively.Subsequently,98.38%Fe was leached from the residue by two stage process,and it is recovered as FePO_(4)·2H_(2)O with a purity of 99.5%by precipitation.Fe and P were present in FePO_(4)·2H_(2)O in amounts of 28.34%and 15.98%,respectively.Additionally,the drift and control of various components were discussed,and cost-benefit analysis was used to assess the feasibility of potential application.展开更多
In this paper,an efficient model structure composed of a second-order resistance-capacitance network and a simply analytical open circuit voltage versus state of charge(SOC) map is applied to characterize the voltage ...In this paper,an efficient model structure composed of a second-order resistance-capacitance network and a simply analytical open circuit voltage versus state of charge(SOC) map is applied to characterize the voltage behavior of a lithium iron phosphate battery for electric vehicles(EVs).As a result,the overpotentials of the battery can be depicted using a second-order circuit network and the model parameterization can be realized under any battery loading profile,without a special characterization experiment.In order to ensure good robustness,extended Kalman filtering is adopted to recursively implement the calibration process.The linearization involved in the calibration algorithm is realized through recurrent derivatives in a recursive form.Validation results show that the recursively calibrated battery model can accurately delineate the battery voltage behavior under two different transient power operating conditions.A comparison with a first-order model indicates that the recursively calibrated second-order model has a comparable accuracy in a major part of the battery SOC range and a better performance when the SOC is relatively low.展开更多
The cathode material of carbon-coated lithium iron phosphate(LiFePO4/C)lithium-ion battery was synthesized by a self-winding thermal method.The material was characterized by X-ray diffraction(XRD)and scanning electron...The cathode material of carbon-coated lithium iron phosphate(LiFePO4/C)lithium-ion battery was synthesized by a self-winding thermal method.The material was characterized by X-ray diffraction(XRD)and scanning electron microscope(SEM).The electrochemical properties of LiFePO4/C materials were measured by the constant current charge-discharge method and cyclic voltammetry.The results showed that the LiFePO4/C material prepared by the self-propagating heat method has a typical olivine crystal structure,and the product had fine grains and good electrochemical properties.The optimal sintering temperature is 700℃,the sintering time is 24 h,the particle size of the lithium iron phosphate material is about 300 nm,and the maximum discharge capacity is 121 mAh/g at 0.1 C rate.展开更多
Nitrate(NO3-)is a widespread pollutant in high-salt wastewater and causes serious harm to human health.Although electrochemical removal of nitrate has been demonstrated to be a promising treatment method,the developme...Nitrate(NO3-)is a widespread pollutant in high-salt wastewater and causes serious harm to human health.Although electrochemical removal of nitrate has been demonstrated to be a promising treatment method,the development of low-cost electro-catalysts is still challenging.In this work,a phosphate modified iron(P-Fe)cathode was prepared for electrochemical removal of nitrate in high-salt wastewater.The phosphate modification greatly improved the activity of iron,and the removal rate of nitrate on P-Fe was three times higher than that on Fe electrode.Further experiments and density functional theory(DFT)calculations demonstrated that the modification of phosphoric acid improved the stability and the activity of the zero-valent iron electrode effectively for NO_(3)^(-) removal.The nitrate was firstly electrochemically reduced to ammonium,and then reacted with the anodic generated hypochlorite to N_(2).In this study,a strategy was developed to improve the activity and stability of metal electrode for NO_(3)^(-)removal,which opened up a new field for the efficient reduction of NO3-removal by metal electrode materials.展开更多
Since lithium iron phosphate cathode material does not contain high-value metals other than lithium,it is therefore necessary to strike a balance between recovery efficiency and economic benefits in the recycling of w...Since lithium iron phosphate cathode material does not contain high-value metals other than lithium,it is therefore necessary to strike a balance between recovery efficiency and economic benefits in the recycling of waste lithium iron phosphate cathode materials.Here,we describe a selective recovery process that can achieve economically efficient recovery and an acceptable lithium leaching yield.Adjusting the acid concentration and amount of oxidant enables selective recovery of lithium ions.Iron is retained in the leaching residue as iron phosphate,which is easy to recycle.The effects of factors such as acid concentration,acid dosage,amount of oxidant,and reaction temperature on the leaching of lithium and iron are comprehensively explored,and the mechanism of selective leaching is clarified.This process greatly reduces the cost of processing equipment and chemicals.This increases the potential industrial use of this process and enables the green and efficient recycling of waste lithium iron phosphate cathode materials in the future.展开更多
LiFePO4 materials have become increasingly popular as a cathode material due to the many benefits they possess including thermal stability, durability, low cost, and long life span. Nevertheless, to broaden the genera...LiFePO4 materials have become increasingly popular as a cathode material due to the many benefits they possess including thermal stability, durability, low cost, and long life span. Nevertheless, to broaden the general appeal of this material for practical electrochemical applications, it would be useful to develop a relatively mild, reasonably simple synthesis method of this cathode material. Herein, we describe a generalizable, 2-step methodology of sustainably synthesizing LiFePO4 by incorporating a template-based, ambient, surfactantless, seedless, U-tube protocol in order to generate size and morphologically tailored, crystalline, phase-pure nanowires. The purity, composition, crystallinity, and intrinsic quality of these wires were systematically assessed using transmission electron microscopy （TEM）, high-resolution TEM （HRTEM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, selected area electron diffraction （SAED）, energy dispersive analysis of X-rays （EDAX）, and high-resolution synchrotron XRD. From these techniques, we were able to determine that there is an absence of any obvious defects present in our wires, supporting the viability of our synthetic approach. Electrochemical analysis was also employed to assess their electrochemical activity. Although our nanowires do not contain any noticeable impurities, we attribute their less than optimal electrochemical rigor to differences in the chemical bonding between our LiFePO4 nanowires and their bulk-like counterparts. Specifically, we demonstrate for the first time experimentally that the Fe-O3 chemical bond plays an important role in determining the overall conductivity of the material, an assertion which is further supported by recent ＂first-principles＂ calculations. Nonetheless, our ambient, solution-based synthesis technique is capable of generating highly crystalline and phase-pure energy-storage-relevant nanowires that can be tailored so as to fabricate different sized materials of reproducible, reliable morphology.展开更多
A study was carried out on contribution of iron pbosphate to phosphorus nutrition of rice plant nnderwaterlogged and moist conditions, respectively, by use of synthetic Fe￣(32) PO_4 . nH_2O, tagging directly the iron...A study was carried out on contribution of iron pbosphate to phosphorus nutrition of rice plant nnderwaterlogged and moist conditions, respectively, by use of synthetic Fe￣(32) PO_4 . nH_2O, tagging directly the ironphophate in calcareous paddy soils.Results showed that under waterlogged condition, similar to iron phosphate in acidic paddy soils, that incalcareous paddy soils was an important source of phosphorus to rice plant, and the amount of phosphorusoriginated from it generally constituted 30-65% of the total phosphorus absorbed by rice plant.展开更多
The open-framework iron phosphate IIIII21.543FeFe(PO) was hydrothermally synthesized and characterized by elemental analysis, IR, EPR, XPS and single crystal X-ray diffraction analysis. The title compound crystallized...The open-framework iron phosphate IIIII21.543FeFe(PO) was hydrothermally synthesized and characterized by elemental analysis, IR, EPR, XPS and single crystal X-ray diffraction analysis. The title compound crystallized in the triclinic, space group P1with a=0.64724(4) nm, b=0.79651(6) nm, c=0.94229(5) nm, =104.447(2)? =108.919(4)? =101.741(4)? V=0.42302(5) nm3, Z=1 and R1 (wR2)=0.0307 (0.0793). Crystal data were collected on a Rigaku R-AXIS RAPID IP diffractometer with Mo K?(=0.071073 nm) at 293(2) K in the range of 2.43埃迹?7.46? The structure of 1 consists of 19 non-hydrogen atoms including three and a half crystallographically in-dependent Fe and three P atoms. Fe(1) connects its symmetrical Fe(1A) through bridging oxygen forming a dimer and the dimers are connected by Fe(4) forming an infinite staircase-like chain. Fe(2) and Fe(3) connect the infinite chains into a layer with bridging oxygen. Layers are interconnected via Fe(4) forming the six-membered and eight-membered channel systems.展开更多
Due to the large error of the traditional battery theoretical model during large-rate discharge for electromagnetic launch,the Shepherd derivative model considering the factors of the pulse cycle condition,temperature...Due to the large error of the traditional battery theoretical model during large-rate discharge for electromagnetic launch,the Shepherd derivative model considering the factors of the pulse cycle condition,temperature,and life is proposed by the Naval University of Engineering.The discharge rate of traditional lithium-ion batteries does not exceed 10C,while that for electromagnetic launch reaches 60C.The continuous pulse cycle condition of ultra-large discharging rate causes many unique electrochemical reactions inside the cells.The traditional model cannot accurately describe the discharge characteristics of the battery.The accurate battery theoretical model is an important basis for system efficiency calculation,precise discharge control,and remaining capacity prediction.To this purpose,an experimental platform for electromagnetic launch is built,and discharge characteristics of the battery under different rate,temperature,and life decay are measured.Through the experimental test and analysis,the reason that the traditional model cannot accurately characterize the large-rate discharge process is analyzed.And a novel battery theoretical model is designed with the help of genetic algorithm,which is integrated with the electromagnetic launch topology.Numerical simulation is compared with the experimental results,which verifies the modeling accuracy for the large-rate discharge.On this basis,a variety of discharge conditions are applied to test the applicability of the model,resulting in better results.Finally,with the continuous cycle-pulse condition in the electromagnetic launch system,the stability and accuracy of the model are confirmed.展开更多
Lithium-iron manganese phosphates(LiFex Mn_(1-x)PO_(4),0.1<x<0.9)have the merits of high safety and high working voltage.However,they also face the challenges of insufficient conductivity and poor cycling stabil...Lithium-iron manganese phosphates(LiFex Mn_(1-x)PO_(4),0.1<x<0.9)have the merits of high safety and high working voltage.However,they also face the challenges of insufficient conductivity and poor cycling stability.Some progress has been achieved to solve these problems.Herein,we firstly summarized the influence of different electrolyte systems on the electrochemical performance of LiFexMn_(1-x)PO_(4),and then discussed the effect of element doping,lastly studied the influences of conductive layer coating and morphology control on the cycling stability.Finally,the prospects and challenges of developing high-cycling LiFexMn_(1-x)PO_(4) were proposed.展开更多
基金supported by the Chilwee Group(No.CWDY-ZH-YJY-202101-001)the Fundamental Research Funds for the Central Universities(No.2042023kf0214)the Starting Funding from Wuhan University.
文摘The efficient recycling of spent lithium iron phosphate(LiFePO_(4),also referred to as LFP)should convert Fe(Ⅱ)to Fe(Ⅲ),which is key to the extraction of Li and separation of Fe and is not well understood.Herein,we systematically study the oxidation of LiFePO_(4)in the air and in the solution containing oxidants such as H_(2)O_(2)and the effect of oxidation on the leaching behaviors of LFP.In the air,O_(2)breaks down the LFP olivine structure at 550℃for 1 h by oxidizing Fe(Ⅱ)to Fe(Ⅲ)in terms of converting LFP to Li_(3)Fe_(2)(PO_(4))_(3)and Fe_(2)O_(3).After that,Li is leached in 0.5 M sulfuric acid solution and is further recycled as Li_(3)PO_(4)with a Li recovery efficiency of 97.48%.Meanwhile,Fe is recovered as FePO_(4)and Fe_(2)O_(3).Compared with H_(2)SO_(4)-H_(2)O_(2),the air oxidation saves H_(2)O_(2)but increases the leaching efficiency of Fe and H_(2)SO_(4)consumption.The discrepancy of Fe leaching efficiency can be attributed to the different leaching mechanisms involving the solid-to-solid and solid-to-liquid-to-solid conversions.Furthermore,the results of the Everbatt model analysis show that the air roasting-H_(2)SO_(4)leaching method has low emission and potentially high income,which is simple and safe.Overall,this work will deepen the understanding of acid leaching of LFP and favorably stimulate the maturation of the LFP recycling technique.
基金National Natural Science Foundation of China(52104294)Fundamental Research Funds for the Central Universities(FRF-TP-19-079A1)。
文摘The soaring demand for smart portable electronics and electric vehicles is propelling the advancements in high-energy–density lithium-ion batteries.Lithium manganese iron phosphate(LiMn_(x)Fe_(1-x)PO_(4))has garnered significant attention as a promising positive electrode material for lithium-ion batteries due to its advantages of low cost,high safety,long cycle life,high voltage,good high-temperature performance,and high energy density.Although LiMn_(x)Fe_(1-x)PO_(4)has made significant breakthroughs in the past few decades,there are still facing great challenges in poor electronic conductivity and Li-ion diffusion,manganese dissolution affecting battery cycling performance,as well as low tap density.This review systematically summarizes the reaction mechanisms,various synthesis methods,and electrochemical properties of LiMn_(x)Fe_(1-x)PO_(4)to analyze reaction processes accurately and guide material preparation.Later,the main challenges currently faced are concluded,and the corresponding various modification strategies are discussed to enhance the reaction kinetics and electrochemical performance of LiMn_(x)Fe_(1-x)PO_(4),including multi-scale particle regulation,heteroatom doping,surface coating,as well as microscopic morphology design.Finally,in view of the current research challenges faced by intrinsic reaction processes,kinetics,and energy storage applications,the promising research directions are anticipated.More importantly,it is expected to provide key insights into the development of high-performance and stable LiMn_(x)Fe_(1-x)PO_(4)materials,to achieve practical energy storage requirements.
基金Funded by the Key Research and Development Projects of Anhui Province(No.2022a05020026)the Key Technologies R&D Program of CNBM(Nos.2021HX0809,2021HX1011)the Anhui Science and Technology Major Project(No.2021e03020009)。
文摘Iron phosphate based glass-ceramics with deliberately added Ce as an active nuclide simulant were prepared by microwave sintering.The sintering characteristics,including phases and structural evolution,and chemical durability were investigated.XRD showed that NaZr_(2)(PO_(4))_(3) and FePO_(4) became the main crystalline phases of glass-ceramics with increasing sintering temperature.SEM revealed the glass-ceramics compactness increased first and then decreased as sintering temperature increased.Raman spectrum showed that,as sintering temperature increased,the network structure of glass-ceramics changed from mainly containing orthophosphate and pyrophosphate to a single orthophosphate.After immersion for 28 days,LR_(Na),LR_(Zr) and LR_(Ce) of the glass-ceramics prepared at 1000℃ were as low as 3.64×10^(-5),0.25×10^(-9) and 5.70×10^(-9)g/m^(2)/d respectively.The results indicate that iron phosphate based glass-ceramics can be prepared by rapid microwave sintering of glass powders and there is a potential of employing such microwave sintering technique in processing of glass-ceramics nuclear waste form.
基金state assignments of Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry,Russian Academy of Sciences(No.124013000692-4 and 122112100037-4).
文摘Lithium iron phosphate(LFP)has found many applications in the field of electric vehicles and energy storage systems.However,the increasing volume of end-of-life LFP batteries poses an urgent challenge in terms of environmental sustainability and resource management.Therefore,the development and implementation of efficient LFP battery recycling methods are crucial to address these challenges.This article presents a novel,comprehensive evaluation framework for comparing different lithium iron phosphate relithiation techniques.The framework includes three main sets of criteria:direct production cost,electrochemical performance,and environmental impact.Each criterion is scored on a scale of 0–100,with higher scores indicating better performance.The direct production cost is rated based on material costs,energy consumption,key equipment costs,process duration and space requirements.Electrochemical performance is assessed by rate capability and cycle stability.Environmental impact is assessed based on CO_(2)emissions.The framework provides a standardized technique for researchers and industry professionals to objectively compare relithiation methods,facilitating the identification of the most promising approaches for further development and scale-up.The total average score across the three criterion groups for electrochemical,chemical,and hydrothermal relithiation methods was approximately 60 points,while sintering scored 39 points,making it the least attractive relithiation technique.Combining approaches outlined in publications with scores exceeding 60,a relithiation scheme was proposed to achieve optimal electrochemical performance with minimal resource consumption and environmental impact.The results demonstrate the framework’s applicability and highlight areas for future research and optimization in lithium iron phosphate cathode recycling.
基金supported by National Natural Science Foundation of China(Grant Nos.52302293 and 22272110)Innovation Project of Education Department of Guangdong Province(Grant No.2023KTSCX124)+2 种基金Shenzhen Science and Technology Program(Grant No.KJZD2023092311460401)Guangdong Higher Education Letter(Grant No.[2024]No.30)Shenzhen Key Laboratory of Applied Technologies of Super-Diamond and Functional Crystals(Grant No.ZDSYS20230626091303007).
文摘With the boom in electric vehicles(EVs),there is an increasing demand for high-performance lithium-ion batteries.Lithium manganese iron phosphate(LMFP)has emerged as an enhanced variation of LiFePO4(LFP),offering an energy density 10%–20%greater than that of LFP.Structural distortion caused by the Jahn–Teller effect decreases the capacity and voltage platform,thus restricting the commercialization of this material.Herein,ideas to overcome these challenges,including the crystal structure of LMFP and strategies to mitigate the Jahn–Teller distortion,are first explored.Then,the migration pathways of Li+during charging and discharging and the phase transition mechanisms that affect the material’s performance are discussed.Next,the optimal Mn:Fe ratio for achieving the desired performance is described.The influences of various synthesis and modification methods on the morphology and structure of LMFP are reviewed.Additionally,different modification techniques,such as doping and coating,to enhance the performance of LMFP are highlighted.Finally,an overview of the current state of research on the recycling and reuse of LMFP is provided.By addressing these key topics,this paper offers a theoretical foundation for the further development of LMFP,thus contributing to its eventual commercialization.
基金financial support from the Hunan Provincial Natural Science Foundation,China(No.2022JJ10074)。
文摘The effective reuse of iron phosphate residue(IPR)is the key issue in the recycling of spent LiFePO_(4)batteries.Therefore,in this study,the reduction leaching of IPR in H_(2)SO_(4)solution by adding iron powder as reducing agent was investigated and compared with direct leaching.The results show that the leaching rate of IPR reached 97%under the optimum reduction leaching conditions.Kinetic studies show that the activation energy for reduction leaching is 12.71 k J/mol,while that of direct leaching is 21.57 k J/mol.Moreover,the reduction leaching time is reduced by half and the acid consumption is reduced by 30% compared to direct leaching with the same leaching rate.This work provides a scientific guidance to the treatment of iron phosphate residue from the recycling of spent LiFePO_(4)batteries.
基金Project(Z20160605230001)supported by Hunan Province Non-ferrous Fund Project,China。
文摘Applying spent lithium iron phosphate battery as raw material,valuable metals in spent lithium ion battery were effectively recovered through separation of active material,selective leaching,and stepwise chemical precipitation.Using stoichiometric Na2S2O8 as an oxidant and adding low-concentration H2SO4 as a leaching agent was proposed.This route was totally different from the conventional methods of dissolving all of the elements into solution by using excess mineral acid.When experiments were done under optimal conditions(Na2S2O8-to-Li molar ratio 0.45,0.30 mol/L H2SO4,60℃,1.5 h),leaching efficiencies of 97.53% for Li^+,1.39%for Fe^3+,and 2.58% for PO4^3−were recorded.FePO4 was then recovered by a precipitation method from the leachate while maintaining the pH at 2.0.The mother liquor was concentrated and maintained at a temperature of approximately 100℃,and then a saturated sodium carbonate solution was added to precipitate Li2CO3.The lithium recovery yield was close to 80%.
文摘Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the p K _a values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was not correlated with p K _a. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.
基金supported by the National Key R&D Program of China(No.2021YFB2402001)the Postgraduate Innovation and Entrepreneurship Practice Project of Anhui Province(No.2022cxcysj013)+2 种基金the China Postdoctoral Science Foundation(No.2022T150615)the Fundamental Research Funds for the Central Universities(No.WK5290000002)supported by Youth Innovation Promotion Association CAS(No.Y201768)。
文摘The safety valve is an important component to ensure the safe operation of lithium-ion batteries(LIBs).However,the effect of safety valve type on the thermal runaway(TR)and gas venting behavior of LIBs,as well as the TR hazard severity of LIBs,are not known.In this paper,the TR and gas venting behavior of three 100 A h lithium iron phosphate(LFP)batteries with different safety valves are investigated under overheating.Compared to previous studies,the main contribution of this work is in studying and evaluating the effect of gas venting behavior and TR hazard severity of LFP batteries with three safety valve types.Two significant results are obtained:(Ⅰ)the safety valve type dominates over gas venting pressure of battery during safety venting,the maximum gas venting pressure of LFP batteries with a round safety valve is 3320 Pa,which is one order of magnitude higher than other batteries with oval or cavity safety valve;(Ⅱ)the LFP battery with oval safety valve has the lowest TR hazard as shown by the TR hazard assessment model based on gray-fuzzy analytic hierarchy process.This study reveals the effect of safety valve type on TR and gas venting,providing a clear direction for the safety valve design.
基金financially supported by the National Key Research and Development Program(Nos.2019YFC1907801,2019YFC1907803 and 2019YFC1907804)the Natural Science Foundation of Hunan(Nos.2021JJ2020066 and 2020JJ4733)+1 种基金the National Natural Science Foundation of China(No.51904340)the Central South University Innovation-Driven Research Program(No.2023CXQD009)。
文摘The recycling of cathode materials from spent lithium-ion battery has attracted extensive attention,but few research have focused on spent blended cathode materials.In reality,the blended materials of lithium iron phosphate and ternary are widely used in electric vehicles,so it is critical to design an effective recycling technique.In this study,an efficient method for recovering Li and Fe from the blended cathode materials of spent LiFePO_(4)and LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)batteries is proposed.First,87%A1 was removed by alkali leaching.Then,91.65%Li,72.08%Ni,64.6%Co and 71.66%Mn were further separated by selective leaching with H_(2)SO_(4)and H_(2)O_(2).Li,Ni,Co and Mn in solution were recovered in the form of Li_(2)CO_(3)and hydroxide respectively.Subsequently,98.38%Fe was leached from the residue by two stage process,and it is recovered as FePO_(4)·2H_(2)O with a purity of 99.5%by precipitation.Fe and P were present in FePO_(4)·2H_(2)O in amounts of 28.34%and 15.98%,respectively.Additionally,the drift and control of various components were discussed,and cost-benefit analysis was used to assess the feasibility of potential application.
基金Project (No. 61004092) supported by the National Natural ScienceFoundation of China
文摘In this paper,an efficient model structure composed of a second-order resistance-capacitance network and a simply analytical open circuit voltage versus state of charge(SOC) map is applied to characterize the voltage behavior of a lithium iron phosphate battery for electric vehicles(EVs).As a result,the overpotentials of the battery can be depicted using a second-order circuit network and the model parameterization can be realized under any battery loading profile,without a special characterization experiment.In order to ensure good robustness,extended Kalman filtering is adopted to recursively implement the calibration process.The linearization involved in the calibration algorithm is realized through recurrent derivatives in a recursive form.Validation results show that the recursively calibrated battery model can accurately delineate the battery voltage behavior under two different transient power operating conditions.A comparison with a first-order model indicates that the recursively calibrated second-order model has a comparable accuracy in a major part of the battery SOC range and a better performance when the SOC is relatively low.
基金Maoming Science and Technology Special Fund Project(Project No.2019018003).Characteristic Innovation Project of Universities in Guangdong Province(Project No.2018KTSCX147).Science and Technology Program of Maoming City(Project No.2020527).
文摘The cathode material of carbon-coated lithium iron phosphate(LiFePO4/C)lithium-ion battery was synthesized by a self-winding thermal method.The material was characterized by X-ray diffraction(XRD)and scanning electron microscope(SEM).The electrochemical properties of LiFePO4/C materials were measured by the constant current charge-discharge method and cyclic voltammetry.The results showed that the LiFePO4/C material prepared by the self-propagating heat method has a typical olivine crystal structure,and the product had fine grains and good electrochemical properties.The optimal sintering temperature is 700℃,the sintering time is 24 h,the particle size of the lithium iron phosphate material is about 300 nm,and the maximum discharge capacity is 121 mAh/g at 0.1 C rate.
基金supported by the National Natural Science Foundation of China (No.22176068)the Research and Innovation Initiatives of WHPU (No.2022J03),the Hubei Provincial Natural Science Foundation (No.2023AFB938)the Scientific research project of Education Department of Hubei Province (No.D20221610).
文摘Nitrate(NO3-)is a widespread pollutant in high-salt wastewater and causes serious harm to human health.Although electrochemical removal of nitrate has been demonstrated to be a promising treatment method,the development of low-cost electro-catalysts is still challenging.In this work,a phosphate modified iron(P-Fe)cathode was prepared for electrochemical removal of nitrate in high-salt wastewater.The phosphate modification greatly improved the activity of iron,and the removal rate of nitrate on P-Fe was three times higher than that on Fe electrode.Further experiments and density functional theory(DFT)calculations demonstrated that the modification of phosphoric acid improved the stability and the activity of the zero-valent iron electrode effectively for NO_(3)^(-) removal.The nitrate was firstly electrochemically reduced to ammonium,and then reacted with the anodic generated hypochlorite to N_(2).In this study,a strategy was developed to improve the activity and stability of metal electrode for NO_(3)^(-)removal,which opened up a new field for the efficient reduction of NO3-removal by metal electrode materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.22125802,and 22078010)Beijing Natural Science Foundation(Grant No.2222017)Big Science Project from BUCT(Grant No.XK180301)。
文摘Since lithium iron phosphate cathode material does not contain high-value metals other than lithium,it is therefore necessary to strike a balance between recovery efficiency and economic benefits in the recycling of waste lithium iron phosphate cathode materials.Here,we describe a selective recovery process that can achieve economically efficient recovery and an acceptable lithium leaching yield.Adjusting the acid concentration and amount of oxidant enables selective recovery of lithium ions.Iron is retained in the leaching residue as iron phosphate,which is easy to recycle.The effects of factors such as acid concentration,acid dosage,amount of oxidant,and reaction temperature on the leaching of lithium and iron are comprehensively explored,and the mechanism of selective leaching is clarified.This process greatly reduces the cost of processing equipment and chemicals.This increases the potential industrial use of this process and enables the green and efficient recycling of waste lithium iron phosphate cathode materials in the future.
文摘LiFePO4 materials have become increasingly popular as a cathode material due to the many benefits they possess including thermal stability, durability, low cost, and long life span. Nevertheless, to broaden the general appeal of this material for practical electrochemical applications, it would be useful to develop a relatively mild, reasonably simple synthesis method of this cathode material. Herein, we describe a generalizable, 2-step methodology of sustainably synthesizing LiFePO4 by incorporating a template-based, ambient, surfactantless, seedless, U-tube protocol in order to generate size and morphologically tailored, crystalline, phase-pure nanowires. The purity, composition, crystallinity, and intrinsic quality of these wires were systematically assessed using transmission electron microscopy （TEM）, high-resolution TEM （HRTEM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, selected area electron diffraction （SAED）, energy dispersive analysis of X-rays （EDAX）, and high-resolution synchrotron XRD. From these techniques, we were able to determine that there is an absence of any obvious defects present in our wires, supporting the viability of our synthetic approach. Electrochemical analysis was also employed to assess their electrochemical activity. Although our nanowires do not contain any noticeable impurities, we attribute their less than optimal electrochemical rigor to differences in the chemical bonding between our LiFePO4 nanowires and their bulk-like counterparts. Specifically, we demonstrate for the first time experimentally that the Fe-O3 chemical bond plays an important role in determining the overall conductivity of the material, an assertion which is further supported by recent ＂first-principles＂ calculations. Nonetheless, our ambient, solution-based synthesis technique is capable of generating highly crystalline and phase-pure energy-storage-relevant nanowires that can be tailored so as to fabricate different sized materials of reproducible, reliable morphology.
文摘A study was carried out on contribution of iron pbosphate to phosphorus nutrition of rice plant nnderwaterlogged and moist conditions, respectively, by use of synthetic Fe￣(32) PO_4 . nH_2O, tagging directly the ironphophate in calcareous paddy soils.Results showed that under waterlogged condition, similar to iron phosphate in acidic paddy soils, that incalcareous paddy soils was an important source of phosphorus to rice plant, and the amount of phosphorusoriginated from it generally constituted 30-65% of the total phosphorus absorbed by rice plant.
基金the National Natural Science Foundation of China (No. 20171010).
文摘The open-framework iron phosphate IIIII21.543FeFe(PO) was hydrothermally synthesized and characterized by elemental analysis, IR, EPR, XPS and single crystal X-ray diffraction analysis. The title compound crystallized in the triclinic, space group P1with a=0.64724(4) nm, b=0.79651(6) nm, c=0.94229(5) nm, =104.447(2)? =108.919(4)? =101.741(4)? V=0.42302(5) nm3, Z=1 and R1 (wR2)=0.0307 (0.0793). Crystal data were collected on a Rigaku R-AXIS RAPID IP diffractometer with Mo K?(=0.071073 nm) at 293(2) K in the range of 2.43埃迹?7.46? The structure of 1 consists of 19 non-hydrogen atoms including three and a half crystallographically in-dependent Fe and three P atoms. Fe(1) connects its symmetrical Fe(1A) through bridging oxygen forming a dimer and the dimers are connected by Fe(4) forming an infinite staircase-like chain. Fe(2) and Fe(3) connect the infinite chains into a layer with bridging oxygen. Layers are interconnected via Fe(4) forming the six-membered and eight-membered channel systems.
基金This study was supported by the National Natural Science Foundation of China(Nos.51607187,51877214,51907203,51925704,and 52107235)the Hubei Provincial Natural Science Foundation of China(Nos.2019CFB371 and 2019CFB373)partially by No.12 Special Financial 349 Aid to China Postdoctoral Science Foundation(No.2019T120972).
文摘Due to the large error of the traditional battery theoretical model during large-rate discharge for electromagnetic launch,the Shepherd derivative model considering the factors of the pulse cycle condition,temperature,and life is proposed by the Naval University of Engineering.The discharge rate of traditional lithium-ion batteries does not exceed 10C,while that for electromagnetic launch reaches 60C.The continuous pulse cycle condition of ultra-large discharging rate causes many unique electrochemical reactions inside the cells.The traditional model cannot accurately describe the discharge characteristics of the battery.The accurate battery theoretical model is an important basis for system efficiency calculation,precise discharge control,and remaining capacity prediction.To this purpose,an experimental platform for electromagnetic launch is built,and discharge characteristics of the battery under different rate,temperature,and life decay are measured.Through the experimental test and analysis,the reason that the traditional model cannot accurately characterize the large-rate discharge process is analyzed.And a novel battery theoretical model is designed with the help of genetic algorithm,which is integrated with the electromagnetic launch topology.Numerical simulation is compared with the experimental results,which verifies the modeling accuracy for the large-rate discharge.On this basis,a variety of discharge conditions are applied to test the applicability of the model,resulting in better results.Finally,with the continuous cycle-pulse condition in the electromagnetic launch system,the stability and accuracy of the model are confirmed.
基金financially supported by the National Natural Science Foundation of China(Nos.51971090 and U21A20311)。
文摘Lithium-iron manganese phosphates(LiFex Mn_(1-x)PO_(4),0.1<x<0.9)have the merits of high safety and high working voltage.However,they also face the challenges of insufficient conductivity and poor cycling stability.Some progress has been achieved to solve these problems.Herein,we firstly summarized the influence of different electrolyte systems on the electrochemical performance of LiFexMn_(1-x)PO_(4),and then discussed the effect of element doping,lastly studied the influences of conductive layer coating and morphology control on the cycling stability.Finally,the prospects and challenges of developing high-cycling LiFexMn_(1-x)PO_(4) were proposed.
