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Effects of pore size and volume on capacity and rate performance for potassium-ion batteries
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作者 Bo Wang Zi-Yu Wu +6 位作者 Si-Chen Deng Di Zhang Qiu-Jun Wang Qu-Jiang Sun Fei Yuan Zhao-Jin Li Wei Wang 《Rare Metals》 2025年第5期3016-3025,共10页
Micro-/mesopore structures in carbon anode are highly desirable for increasing active sites and accelerating ion migration,favoring high capacity and rate performance.However,some structure-performance relationships s... Micro-/mesopore structures in carbon anode are highly desirable for increasing active sites and accelerating ion migration,favoring high capacity and rate performance.However,some structure-performance relationships still need to be clarified,and an in-depth understanding of how pore size and volume affect capacity and rate performance has rarely been mentioned.Herein,a series of carbon nanosheets with different micro-/mesopore sizes and volumes are precisely prepared.Detailed experimental analyses demonstrate that micropore volume rather than size is tightly responsible for capacity,resulting from its“accommodation effect”for ions.Conversely,mesopore size instead of volume is closely related to rate performance,which can be ascribed to its“channels effect”for ions.Capacity and rate performance first increase and then decrease with increasing micropore volume and mesopore size.In this work,the sample featured with the optimal micropore volume(1.6 cm^(3)·g^(-1))and mesopore size(2.55 nm)delivers the highest capacity(453 mAh·g^(-1)at 0.5 A·g^(-1))and excellent rate performance(235.1 mAh·g^(-1)at 2 A·g^(-1)).This work provides a new insight into the understanding of micro-/mesopore parameters and their effect on capacity and rate performance. 展开更多
关键词 Micro-/mesopore structure Carbon anode Potassium-ion battery Capacity rate performance
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Web-in-web carbon cathode design unlocking high area capacitance and high-rate performance for Zn-ion hybrid supercapacitors
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作者 Qian Gong João Cunha +6 位作者 Liming Zhao Zhipeng Yu Xiaoyu Zhang Shunrui Luo Najeeb ur Rehman Lashari Xiaona Wang Yurong Zhou 《Rare Metals》 2025年第10期7281-7292,共12页
Zn-ion hybrid supercapacitors(ZHSCs),as emerging energy storage systems,combine high energy and power density with cost-effectiveness and safety,attracting significant attention.However,due to the inherent energy stor... Zn-ion hybrid supercapacitors(ZHSCs),as emerging energy storage systems,combine high energy and power density with cost-effectiveness and safety,attracting significant attention.However,due to the inherent energy storage mechanism and the diminishing marginal benefits of increased porosity on capacitance,engineering porous nanostructures to develop carbon materials with ideal architectures is crucial for achieving high performance.Herein,a novel web-in-web porous carbon/carbon nanotubes(CNTs)composite has been proposed,fabricated by a simple phase separation method and two-step carbonization.During pre-oxidation,gradual air oxidation induces the formation of an O,N co-doped polymer-chain template,which subsequently transforms into a graphitized web during high-temperature carbonization.The optimized web-in-web structure,enriched with abundant active sites,accelerates mass transport and charge transfer kinetics.When assembled in ZHSCs,the web-in-web cathode achieved a high area capacitance(14,309 mF cm^(-2))with high mass loading(38.2 mg cm^(-2)).It delivered excellent high-rate performance at 50 mA cm^(-2)with a capacitance retention of 83%after 10,000 cycles,also boosting a high energy density(1452.7μWh cm^(-2))and power density(30.8 mW cm^(-2)).Furthermore,ex situ characterization and in situ electrochemical analyses reveal hybrid energy storage mechanisms,involving both physical/chemical adsorption and precipitation/dissolution across different potential regions.This study provides a promising strategy for designing high-area-capacitance carbon cathodes boosting high-performance ZHSCs. 展开更多
关键词 Carbon nanotubes Zn-ion hybrid supercapacitors Area capacitance rate performance
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High-efficiently doping nitrogen in kapok fiber-derived hard carbon used as anode materials for boosting rate performance of sodium-ion batteries 被引量:3
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作者 Tianyun Zhang Tian Zhang +1 位作者 Fujuan Wang Fen Ran 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第9期472-482,共11页
The engineering of plant-based precursor for nitrogen doping has become one of the most promising strategies to enhance rate capability of hard carbon materials for sodium-ion batteries;however,the poor rate performan... The engineering of plant-based precursor for nitrogen doping has become one of the most promising strategies to enhance rate capability of hard carbon materials for sodium-ion batteries;however,the poor rate performance is mainly caused by lack of pyridine nitrogen,which often tends to escape because of high temperature in preparation process of hard carbon.In this paper,a high-rate kapok fiber-derived hard carbon is fabricated by cross-linking carboxyl group in 2,6-pyridinedicarboxylic acid with the exposed hydroxyl group on alkalized kapok with assistance of zinc chloride.Specially,a high nitrogen doping content of 4.24%is achieved,most of which are pyridine nitrogen;this is crucial for improving the defect sites and electronic conductivity of hard carbon.The optimized carbon with feature of high nitrogen content,abundant functional groups,degree of disorder,and large layer spacing exhibits high capacity of 401.7 mAh g^(−1)at a current density of 0.05 A g^(−1),and more importantly,good rate performance,for example,even at the current density of 2 A g^(−1),a specific capacity of 159.5 mAh g^(−1)can be obtained.These findings make plant-based hard carbon a promising candidate for commercial application of sodium-ion batteries,achieving high-rate performance with the enhanced pre-cross-linking interaction between plant precursors and dopants to optimize aromatization process by auxiliary pyrolysis. 展开更多
关键词 Kapok fiber Hard carbon Electrode materials rate performance Sodium-ion batteries
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Recent Progress in Improving Rate Performance of Cellulose-Derived Carbon Materials for Sodium-Ion Batteries 被引量:1
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作者 Fujuan Wang Tianyun Zhang +2 位作者 Tian Zhang Tianqi He Fen Ran 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第8期102-147,共46页
Cellulose-derived carbon is regarded as one of the most promising candidates for high-performance anode materials in sodium-ion batteries;however,its poor rate performance at higher current density remains a challenge... Cellulose-derived carbon is regarded as one of the most promising candidates for high-performance anode materials in sodium-ion batteries;however,its poor rate performance at higher current density remains a challenge to achieve high power density sodium-ion batteries.The present review comprehensively elucidates the structural characteristics of cellulose-based materials and cellulose-derived carbon materials,explores the limitations in enhancing rate performance arising from ion diffusion and electronic transfer at the level of cellulose-derived carbon materials,and proposes corresponding strategies to improve rate performance targeted at various precursors of cellulose-based materials.This review also presents an update on recent progress in cellulose-based materials and cellulose-derived carbon materials,with particular focuses on their molecular,crystalline,and aggregation structures.Furthermore,the relationship between storage sodium and rate performance the carbon materials is elucidated through theoretical calculations and characterization analyses.Finally,future perspectives regarding challenges and opportunities in the research field of cellulose-derived carbon anodes are briefly highlighted. 展开更多
关键词 CELLULOSE Hard carbon Anode materials rate performance Sodium-ion batteries
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Effect of sintering temperature on cycling performance and rate performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2 被引量:2
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作者 李向群 熊训辉 +1 位作者 王志兴 陈启元 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第12期4023-4029,共7页
LiNi0.8Co0.1Mn0.1O2 powder was prepared by mixing LiOH·H2O and co-precipitated Ni0.8Co0.1Mn0.1(OH)2 at a molar ratio of 1:1.05, followed by sintering at different temperatures. The effects of temperature on th... LiNi0.8Co0.1Mn0.1O2 powder was prepared by mixing LiOH·H2O and co-precipitated Ni0.8Co0.1Mn0.1(OH)2 at a molar ratio of 1:1.05, followed by sintering at different temperatures. The effects of temperature on the morphology, structure and electrochemical performance were extensively studied. SEM and XRD results demonstrate that the sintering temperature has large influence on the morphology and structure and suitable temperature is very important to obtain spherical materials and suppresses the ionic distribution. The charge-discharge tests show that the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 powders becomes better with the increase of temperature from 700 ℃ to 750 ℃ and higher temperature will deteriorate the performance. Although both of materials obtained at 750 ℃ and 780 ℃ demonstrate almost identical cyclic stability at 2C rate, which delivers 71.9%retention after 200 cycles, the rate performance of powder calcined at 780 ℃ is much poorer than that at 750 ℃. The XRD results demonstrate that the poor performance is ascribed to more severe ionic distribution caused by higher temperature. 展开更多
关键词 lithium ion battery LiNi0.8CO0.1Mn0.1O2 sintering temperature cycling performance rate performance
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Research Progress in Improving the Rate Performance of LiFePO_4 Cathode Materials 被引量:10
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作者 Sixu Deng Hao Wang +2 位作者 Hao Liu Jingbing Liu Hui Yan 《Nano-Micro Letters》 SCIE EI CAS 2014年第3期209-226,共18页
Olivine lithium iron phosphate(Li Fe PO4) is considered as a promising cathode material for high power density lithium ion battery due to its high capacity, long cycle life, environmental friendly, low cost, and safet... Olivine lithium iron phosphate(Li Fe PO4) is considered as a promising cathode material for high power density lithium ion battery due to its high capacity, long cycle life, environmental friendly, low cost, and safety consideration. The theoretical capacity of Li Fe PO4 based on one electron reaction is 170 m Ah g-1at the stable voltage plateau of 3.5 V vs. Li/Li+. However, the instinct drawbacks of olivine structure induce a poor rate performance, resulting from the low lithium ion diffusion rate and low electronic conductivity.In this review, we summarize the methods for enhancing the rate performance of Li Fe PO4 cathode materials,including carbon coating, elements doping, preparation of nanosized materials, porous materials and composites,etc. Meanwhile, the advantages and disadvantages of above methods are also discussed. 展开更多
关键词 LIFEPO4 Lithium ion battery rate performance
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Methods of improving the initial Coulombic efficiency and rate performance of both anode and cathode materials for sodium-ion batteries 被引量:5
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作者 Nkongolo Tshamala Aristote Kangyu Zou +6 位作者 Andi Di Wentao Deng Baowei Wang Xinglan Deng Hongshuai Hou Guoqiang Zou Xiaobo Ji 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第2期730-742,共13页
Sodium-ion batteries(SIBs) have gained more scientists’ interest, owing to some facts such as the natural abundance of Na, the similarities of physicochemical characteristics between Li and Na. The irreversible Na+io... Sodium-ion batteries(SIBs) have gained more scientists’ interest, owing to some facts such as the natural abundance of Na, the similarities of physicochemical characteristics between Li and Na. The irreversible Na+ions consumption during the first cycle of charge/discharge process(due to the formation of the solid electrolyte interface(SEI) on the electrode surface and other irreversible reactions) is the factor that determines high performance SIBs and largely reduces the capacity of the full cell SIBs. Thus, the initial coulombic efficiency(ICE) of SIBs for both anode and cathode materials, is a key parameter for high performance SIBs, and the point is to increase the transport rate of the Na+ions. Therefore, developing SIBs with high ICE and rate performance becomes vital to boost the commercialization of SIBs. Here we provide a review on the methods to improve the ICE and the rate performance, by summarizing some methods of improving the ICE and rate performance of the anode and cathode materials for SIBs, and end by a conclusion with some perspectives and recommendations. 展开更多
关键词 Initial coulombic efficiency rate performance Sodium-ion batteries Anode materials Cathode materials
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Conducting network interface modulated rate performance in LiFePO_(4)/C cathode materials 被引量:4
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作者 Ji-Ming Peng Zhi-Qiang Chen +5 位作者 Yu Li Si-Jiang Hu Qi-Chang Pan Feng-Hua Zheng Hong-Qiang Wang Qing-Yu Li 《Rare Metals》 SCIE EI CAS CSCD 2022年第3期951-959,共9页
Carbon can play a critical role in electrode,especially for LiFePO_(4)cathode,not only serving as con-tinuous conducting network for electron pathway,but also boosting Li^(+) diffusion through providing sufficient ele... Carbon can play a critical role in electrode,especially for LiFePO_(4)cathode,not only serving as con-tinuous conducting network for electron pathway,but also boosting Li^(+) diffusion through providing sufficient elec-trons.Here,we report the modulation of electrode/elec-trolyte interface to yield excellent rate performance by creating cross-linked conducting carbon network in LiFePO_(4)/C cathode material.Such conducting networks inhibit agglomeration and growth of LiFePO_(4)/C primary particles and hence lead to a short Li^(+)diffusion pathway.Furthermore,it also offers fast electron transmission rate and efficient electron for Li storage in the LiFePO_(4)sheath.The LiFePO_(4)/C with carbon nanotubes(CNTs)delivers a discharge capacity of 150.9 mAh·g^(-1) at 0.1C(initial Coulombic efficiency of 96.4%)and an enhanced rate capability(97.2 mAh·g^(-1) at 20.0C).Importantly,it exhi-bits a high cycle stability with a capacity retention of 90.3%even after 800 cycles at 5.0C(0.85 A·g^(-1)).This proposed interface design can be applied to a variety of battery electrodes that face challenges in electrical contact and ion transport. 展开更多
关键词 Lithium-ion battery Cathode material LiFePO_(4) rate performance
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Understanding De-protonation Induced Formation of Spinel Phase in Li-rich Layered Oxides for Improved Rate Performance 被引量:1
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作者 李保云 李广社 +3 位作者 张丹 范建明 冯涛 李莉萍 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第11期1723-1736,共14页
Constructing layered-spinel composites is important to improve the rate performance of lithium-rich layered oxides.However,up to now,the effect of microstructure of composites on the rate performance has not been well... Constructing layered-spinel composites is important to improve the rate performance of lithium-rich layered oxides.However,up to now,the effect of microstructure of composites on the rate performance has not been well investigated.In this study,a series of samples were prepared by a simple protonation and de-protonation for the pristine layered material(LiMnNiCoO)obtained by sol-gel method.The characterizations of XRD,Raman and oxidation-reduction potentials of charge-discharge curves demonstrated that these samples after de-protonation are layered-spinel composites.When these composites were tested as a cathode of lithium-ion batteries,the sample treated with 0.1 M of nitric acid exhibited higher discharge capacities at each current density than that of other composites.The outstanding rate performance is attributed to the high concentration of conduction electron resulting from the low average valence state(44.2%of Ni)as confirmed by its high conductivity(1.124×10??mat39800Hz)and ambient temperature magnetic susceptibility(8.40×10emu/Oe?mol).This work has a guiding significance for the synthesis of high rate performance of lithium battery cathode materials. 展开更多
关键词 protonation and de-protonation layered-spinel composites rate performance conduction electron
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Improving Cyclic Stability and Rate Performance of Lithium Ion Batteries Using La^(3+)Modified LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)Cathode Materials
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作者 杜玉喆 RUAN Zhefei +1 位作者 ZHANG Ruiming 张海宁 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第4期735-742,共8页
La_(4)NiLiO_(8)-coated NCM622 samples were prepared through a sol-gel method,and the electrochemical performance as cathode materials was investigated.It is revealed that part of the introduced La^(3+)ions produce a c... La_(4)NiLiO_(8)-coated NCM622 samples were prepared through a sol-gel method,and the electrochemical performance as cathode materials was investigated.It is revealed that part of the introduced La^(3+)ions produce a coating layer on the surface of NCM622 particles,while the rest occupy the 3b position of the lattice.The optimized sample exhibits a capacity retention of 96.54%after 100 cycles under 1C rate with a discharge specific capacity of 117.54 mAh·g^(-1)under 5C rate,much higher than those of the unmodified sample.The results show that the addition of La^(3+)ion can greatly improve the cyclic stability and the rate performance of NCM622. 展开更多
关键词 lithium ion batter La^(3+)doping NCM622 cycling stability rate performance
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Analysis of the factors affecting rate performance of LiFePO_4 lithium-ion batteries
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作者 WANG Jingjie XU Limin YANG Bing 《Baosteel Technical Research》 CAS 2020年第2期15-21,共7页
In this paper,a water-based binder was used in LiFePO4 Li-ion batteries and the factors affecting the battery performance were analyzed. The type and amount of conductive agent and the amount of binder were found to h... In this paper,a water-based binder was used in LiFePO4 Li-ion batteries and the factors affecting the battery performance were analyzed. The type and amount of conductive agent and the amount of binder were found to have a significant impact on the rate performance of LiFePO4 Li-ion batteries. The impact of the two types of binders used in the test was not obvious. 展开更多
关键词 water-based pulping LIFEPO4 button battery rate performance
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Factors affecting specific capacity and rate performance of aqueous Li4Ti5O12 battery
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作者 XU Limin WANG Jingjie Yang Bing 《Baosteel Technical Research》 CAS 2019年第4期39-47,共9页
The use of an aqueous slurry in the manufacture of lithium ion batteries has the advantages of being environmentally friendly,harmless to the human body,and low in production cost.In this study,the factors affecting t... The use of an aqueous slurry in the manufacture of lithium ion batteries has the advantages of being environmentally friendly,harmless to the human body,and low in production cost.In this study,the factors affecting the specific capacity and rate performance of the aqueous Li4Ti5O12 battery were studied,including the Li4Ti5O12 structure,aqueous binder,conductive agent,and surface density.The results show that a spherical secondary particle structure of Li4Ti5O12 is beneficial to its discharge rate performance.In addition,an aqueous binder with high conductivity improves the specific capacity and high rate charge/discharge performance of the battery,and when the amount of binder is 3%,the Li4Ti5O12 battery performs better.A chain structure in the conductive agent also improves the specific capacity and discharge rate performance of the Li4Ti5O12 battery,and increases the degree to which the discharge rate performance of the conductive agent can be further improved.Lastly,the lower the surface density,the better the rate performance of the Li4Ti5O12 battery. 展开更多
关键词 aqueous lithium ion battery LI4TI5O12 specific capacity rate performance
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Tailored architecture of composite electrolyte for all-solid-state sodium batteries with superior rate performance and cycle life 被引量:1
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作者 Xiang Guan Zhenhua Jian +5 位作者 Xingan Liao Wenchao Liao Yanfei Huang Dazhu Chen Robert K.Y.Li Chen Liu 《Nano Research》 SCIE EI CSCD 2024年第5期4171-4180,共10页
Seeking for composite electrolytes reinforced all-solid-state sodium ion batteries with superior long lifespan and rate performance remains a great challenge.Here,a unique strategy to tailor the architecture of compos... Seeking for composite electrolytes reinforced all-solid-state sodium ion batteries with superior long lifespan and rate performance remains a great challenge.Here,a unique strategy to tailor the architecture of composite electrolyte via inserting polymer chains into a small quantity of sulfate sodium grafted C_(48)0H_(28)O_(32)Zr_(6)(UIOSNa)is proposed.The intimate contact between polymer segments and UIOSNa with limited pore size facilitates the anion immobilization of sodium salts and reduction of polymer crystallinity,thereby providing rapid ion conduction and reducing the adverse effect caused by the immigration of anions.The tNa+grafting of-SO_(3)Na groups on fillers allows the free movement of more sodium ions to further improve and ionic conductivity.Consequently,even with the low content of UIOSNa fillers,a high ionic conductivity of 6.62×10^(-4) S·cm^(-1) at 60℃ and a transference number of 0.67 for the special designed composite electrolyte are achieved.The assembled all-solid-state sodium cell exhibits a remarkable rate performance for 500 cycles with 95.96%capacity retention at a high current rate of 4 C.The corresponding pouch cell can stably work for 1000 cycles with 97.03%capacity retention at 1 C,which is superior to most of the reported composite electrolytes in the literature. 展开更多
关键词 solid state sodium battery composite electrolyte rate performance cycle life
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V_(2)CT_(X)MXene-derived ammonium vanadate with robust carbon skeleton for superior rate aqueous zinc-ion batteries
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作者 Xiaojun Wang Yizhou Zhang +4 位作者 Linwei Guo Jianwei Li Peng Wang Lei Yang Zhiming Liu 《Chinese Chemical Letters》 2025年第8期530-537,共8页
Layered ammonium vanadate has become a promising cathode material for aqueous zinc ion batteries(ZIBs)due to its small mass and large ionic radius of ammonium ions as well as the consequent large layer spacing and hig... Layered ammonium vanadate has become a promising cathode material for aqueous zinc ion batteries(ZIBs)due to its small mass and large ionic radius of ammonium ions as well as the consequent large layer spacing and high specific capacity.However,the irreversible de-ammoniation caused by N·H···O bonds damaged would impair cycle life of ZIBs and the strong electrostatic interaction between Zn^(2+)and V-O frame could slower the mobility of Zn^(2+).Furthermore,the thermal instability of ammonium vanadate also limits the use of common carbon coating modification method to solve the problem.Herein,V_(2)CT_(X)MXene was innovatively selected as a bifunctional source to in-situ derivatized(NH_(4))_(2)V_(8)O_(20)·x H_(2)O with amorphous carbon-coated(NHVO@C)via one-step hydrothermal method in relatively moderate temperature.The amorphous carbon shell derived from the V_(2)CT_(X)MXene as a conductive framework to effectively improve the diffusion kinetics of Zn^(2+)and the robust carbon skeleton could alleviate the ammonium dissolution during long-term cycling.As a result,zinc ion batteries using NHVO@C as cathode exhibit superior electrochemical performance.Moreover,the assembled foldable or high loading(10.2 mg/cm^(2))soft-packed ZIBs further demonstrates its practical application.This study provided new insights into the development of the carbon cladding process for thermally unstable materials in moderate temperatures. 展开更多
关键词 Ammonium vanadate Carbon skeleton Ammonium dissolution Superior rate performance Zinc ionbatteries
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Seaweed-Inspired NH_(4)V_(4)O_(10)-Ti_(3)C_(2)T_(x) MXene/Carbon Nanofibers for High-Performance Aqueous Zinc-Ion Batteries
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作者 Seulgi Kim Seojin Woo +4 位作者 Segi Byun Hyunki Kim Han Seul Kim Sang Mun Jeong Dongju Lee 《Energy & Environmental Materials》 2025年第3期49-57,共9页
Aqueous zinc-ion batteries(AZIBs)have emerged as promising,practical energy storage devices based on their non-toxic nature,environmental friendliness,and high energy density.However,excellent rate characteristics and... Aqueous zinc-ion batteries(AZIBs)have emerged as promising,practical energy storage devices based on their non-toxic nature,environmental friendliness,and high energy density.However,excellent rate characteristics and stable long-term cycling performance are essential.These essential aspects create a need for superior cathode materials,which represents a substantial challenge.In this study,we used MXenes as a framework for NH_(4)V_(4)O_(10)(NVO)construction and developed electrodes that combined the high capacity of NVO with the excellent conductivity of MXene/carbon nanofibers(MCNFs).We explored the electrochemical characteristics of electrodes with varying NVO contents.Considering the distinctive layered structure of NVO,the outstanding conductivity of MCNFs,and the strong synergies between the two components.NVO-MCNFs exhibited better charge transfer compared with earlier materials,as well as more ion storage sites,excellent conductivity,and short ion diffusion pathways.A composite electrode with optimized NVO content exhibited an excellent specific capacitance of 360.6mAh g^(-1) at 0.5 A g^(-1) and an outstanding rate performance.In particular,even at a high current density of 10 A g^(-1),the 32NVO-MCNF exhibited impressive cycling stability:88.6%over 2500 cycles.The mechanism involved was discovered via comprehensive characterization.We expect that the fabricated nanofibers will be useful in energy storage and conversion systems. 展开更多
关键词 Aqueous Zinc Ion Batteries seaweed inspired Ti C Tx MXene superior cathode materialswhich Electrochemical Characteristics energy storage devices rate performance Carbon Nanofibers
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Pore-structure regulation and heteroatom doping of activated carbon for supercapacitors with excellent rate performance and power density 被引量:4
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作者 Jian Zhang Huachao Yang +5 位作者 Zhesong Huang HuiHui Zhang Xinchao Lu Jianhua Yan Kefa Cen Zheng Bo 《Waste Disposal and Sustainable Energy》 EI CSCD 2023年第3期417-426,共10页
Activated carbon(AC)has attracted tremendous research interest as an electrode material for supercapacitors owing to its high specific surface area,high porosity,and low cost.However,AC-based supercapacitors suffer fr... Activated carbon(AC)has attracted tremendous research interest as an electrode material for supercapacitors owing to its high specific surface area,high porosity,and low cost.However,AC-based supercapacitors suffer from limited rate performance and low power density,which mainly arise from their inherently low electrical conductivity and sluggish ion dynamics in the micropores.Here,we propose a simple yet effective strategy to address the aforementioned issue by nitrogen/fluorine doping and enlarging the micropore size.During the treatment,the decomposition products of NH4F react with the carbon atoms to dope the AC with nitrogen/fluorine and simultaneously enlarge the pores by etching.The treated AC shows a higher specific surface area of 1826 m2 g^(−1)(by~15%),more micropores with a diameter around 0.93 nm(by~33%),better wettability(contact angle decreased from 120°to 45°),and excellent electrical conductivity(96 S m^(−1))compared with untreated AC(39 S m^(−1)).The as-fabricated supercapacitors demonstrate excellent specific capacitance(26 F g^(−1)at 1 A g^(−1)),significantly reduced electrical resistance(by~50%),and improved rate performance(from 46.21 to 64.39%at current densities of 1 to 20 A g^(−1)).Moreover,the treated AC-based supercapacitor achieves a maximum energy density of 25 Wh kg^(−1)at 1000 W kg^(−1)and a maximum power density of 10,875 W kg^(−1)at 15 Wh kg^(−1),which clearly outperforms pristine AC-based supercapacitors.This synergistic treatment strategy provides an effective way to improve the rate performance and power density of AC-based supercapacitors. 展开更多
关键词 Activated carbon Heteroatom doping Pore-size modification rate performance SUPERCAPACITORS
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Hierarchically Micro/Nanostructured Current Collectors Induced by Ultrafast Femtosecond Laser Strategy for High-Performance Lithium-ion Batteries 被引量:2
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作者 Yaya Wang Zexu Zhao +8 位作者 Jiang Zhong Tao Wang Lei Wang Hanjiao Xu Jinhui Cao Jinhao Li Guanhua Zhang Huilong Fei Jian Zhu 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2022年第3期969-976,共8页
Commercial Cu and Al current collectors for lithium-ion batteries(LIBs)possess high electrical conductivity,suitable chemical and electrochemical stability.However,the relatively flat surface of traditional current co... Commercial Cu and Al current collectors for lithium-ion batteries(LIBs)possess high electrical conductivity,suitable chemical and electrochemical stability.However,the relatively flat surface of traditional current collectors causes weak bonding strength and poor electrochemical contact between current collectors and electrode materials,resulting in potential detachment of active materials and rapid capacity degradation during extended cycling.Here,we report an ultrafast femtosecond laser strategy to manufacture hierarchical micro/nanostructures on commercial Al and Cu foils as current collectors for high-performance LIBs.The hierarchically micro/nanostructured current collectors(HMNCCs)with high surface area and roughness offer strong adhesion to active materials,fast electronic delivery of entire electrodes,significantly improving reversible capacities and cyclic stability of HMNCCs based LIBs.Consequently,LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM523)cathode with Al HMNCC generated a high reversible capacity after 200 cycles(25%higher than that of cathode with Al CC).Besides,graphite anode with Cu HMNCC also maintained prominent reversible capacity even after 600 cycles.Moreover,the full cell assembled by graphite anode with Cu HMNCC and NCM523 cathode with Al HMNCC achieved high reversible capacity and remarkable cycling stability under industrial-grade mass loading.This study provides promising candidate for achieving high-performance LIBs current collectors. 展开更多
关键词 currentcollectors femtosecondlaserstrategy hierarchical micro/nanostructures high rate performance lithium-ion battery
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Partial surface phase transformation of Li_(3)VO_(4) that enables superior rate performance and fast lithium-ion storage 被引量:6
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作者 Xiaoqing Liu Liping Li Guangshe Li 《Tungsten》 2019年第4期276-286,共11页
Li_(3)VO_(4) is a promising electrode material for next-generation lithium-ion batteries(LIBs)due to its excellent specific capac-ity(592 mAh g^(−1)),suitable discharge voltage(0.5-1.0 V),and moderate volume change up... Li_(3)VO_(4) is a promising electrode material for next-generation lithium-ion batteries(LIBs)due to its excellent specific capac-ity(592 mAh g^(−1)),suitable discharge voltage(0.5-1.0 V),and moderate volume change upon charge/discharge,while it still suffers from low electronic conductivity that usually gives a poor rate capability,low initial coulombic efficiency,and large polarization,imposing a challenge on its practical applications.In this work,a partial surface phase transformation of Li_(3)VO_(4) was initiated via a freeze-drying method followed by a heat treatment in inert gas.Using this method,Li_(3)VO_(4) was integrated with a conductive layer LiVO_(2) and carbon matrix.The synergistic effect among Li_(3)VO_(4),LiVO_(2) layer,and carbon matrix was systematically studied by optimizing the treatment conditions.When treated at 600°C in Ar,Li_(3)VO_(4)-based composite delivered outstanding electrochemical properties,as expressed by a specific capacity(689 mAh g^(−1) at 0.1 A g^(−1) after 100 cycles),rate performance(i.e.,448 mAh g^(−1) at 2 A g^(−1)),and longtime cycle stability(523 mAh g^(−1) after 200 cycles at 0.2 A g^(−1)),which are superior to those without LiVO_(2) conductive layer when treated at the same temperature in air.The findings reported in this work may offer novel hints of preparing more advanced anodes and promote the applications of vanadate materials such as Li_(3)VO_(4) for next-generation lithium-ion batteries. 展开更多
关键词 Li_(3)VO_(4) LiVO_(2) rate performance Electronic conductivity Li^(+)diffusion
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Improving rate performances of Li-rich layered oxide by the co-doping of Sn and K ions 被引量:1
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作者 Bao Li Xinbo Wang +4 位作者 Yibo Gao Bao Wang Jinxu Qiu Xu Cheng Dongmei Dai 《Journal of Materiomics》 SCIE EI 2019年第2期149-155,共7页
The specific capacities and power performances of conventional cathode materials are still needed to improve in order to meet the demand for electrical vehicles.Li-rich layered oxide delivers a high specific capacity,... The specific capacities and power performances of conventional cathode materials are still needed to improve in order to meet the demand for electrical vehicles.Li-rich layered oxide delivers a high specific capacity,but poor rate performances.Chemical doping is an effective way to address this challenge due to the expanded crystal lattice.Unlike a single ion substitution in the literature,here Li-rich layered oxides were doped by Sn and K to achieve the favorite rate performance,where Sn and K were assumed to replace transition metal ion and Li ion,respectively.Results indicate the co-doped samples result in an increasing capacity retention by more than 40%from 107.9(contrast sample)to 151.5 mAh g^(-1)(co-doped sample)at 10 C-rate.Electrochemical impedance spectroscopy(EIS)and calculated diffusion coefficient of Li^(+) also confirmed the favorite rate performances for co-doped sample.Combining results of Rietveld structure refinement,we proposed that the reason for rate performances comes from the enlarged crystal lattices,which provides a smooth diffusion tunnel for Lithium ions during the charge/discharge processes.The as-adopted method provides a possibility to achieve the improved rate performances by co-doping big-size ions at the different crystal sites. 展开更多
关键词 Li-rich layered oxide rate performance Sn-doping K-doping Crystal lattice Solid state reaction
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Decay rate performance approach for stabilization continuous fuzzy models using their discretized forms
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作者 Ameni Ellouze François Delmotte +2 位作者 Jimmy Lauber Mohamed Chtourou Mohamed Ksantini 《International Journal of Intelligent Computing and Cybernetics》 EI 2015年第4期383-400,共18页
Purpose–The purpose of this paper is to deal with the stabilization of the continuous Takagi Sugeno(TS)fuzzy models using their discretized forms based on the decay rate performance approach.Design/methodology/appro... Purpose–The purpose of this paper is to deal with the stabilization of the continuous Takagi Sugeno(TS)fuzzy models using their discretized forms based on the decay rate performance approach.Design/methodology/approach–This approach is structured as follows:first,a discrete model is obtained from the discretization of the continuous TS fuzzy model.The discretized model is obtained from the Euler approximation method which is used for several orders.Second,based on the decay rate stabilization conditions,the gains of a non-PDC control law ensuring the stabilization of the discrete model are determined.Third by keeping the values of the gains,the authors determine the values of the performance criterion and the authors check by simulation the stability of the continuous TS fuzzy models through the zero order hold.Findings–The proposed idea lead to compare the performance continuous stability results with the literature.The comparison is,also,taken between the quadratic and non-quadratic cases.Originality/value–Therefore,the originality of this paper consists in the improvement of the continuous fuzzy models by using their discretized models.In this case,the effect of the discretization step on the performances of the continuous TS fuzzy models is studied.The usefulness of this approach is shown through two examples. 展开更多
关键词 Non-linear control STABILIZATION Continuous Takagi Sugeno(TS)fuzzy models Decay rate performance approach Euler discretization Non-PDC control
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