A green environmental protection and enhanced leaching process was proposed to recover all elements from spent lithium iron phosphate(LiFePO_(4)) lithium batteries.In order to reduce the influence of Al impurity in th...A green environmental protection and enhanced leaching process was proposed to recover all elements from spent lithium iron phosphate(LiFePO_(4)) lithium batteries.In order to reduce the influence of Al impurity in the recovery process,NaOH was used to remove impurity.After impurity removal,the spent LiFePO_(4) cathode material was used as raw material under the H_(2)SO_(4) system,and the pressure oxidation leaching process was adopted to achieve the preferential leaching of lithium.The E-pH diagram of the Fe-P-Al-H_(2)O system can determine the stable region of each element in the recovery process of spent LiFePO_(4)Li-batteries.Under the optimal conditions(500 r·min^(-1),15 h,363.15 K,0.4 MPa,the liquid-solid ratio was 4:1 ml·g^(-1)and the acid-material ratio was 0.29),the leaching rate of Li was 99.24%,Fe,Al,and Ti were 0.10%,2.07%,and 0.03%,respectively.The Fe and P were precipitated and recovered as FePO_(4)·2H_(2)O.The kinetic analysis shows that the process of high-pressure acid leaching of spent LiFePO_(4) materials depends on the surface chemical reaction.Through the life cycle assessment(LCA)of the spent LiFePO_(4) whole recovery process,eight midpoint impact categories were selected to assess the impact of recovery process.The results can provide basic environmental information on production process for recycling industry.展开更多
Carbon nitrides with two-dimensional layered structures and high theoretical capacities are attractive as anode materials for sodium-ion batteries while their low crystallinity and insufficient structural stability st...Carbon nitrides with two-dimensional layered structures and high theoretical capacities are attractive as anode materials for sodium-ion batteries while their low crystallinity and insufficient structural stability strongly restrict their practical applications.Coupling carbon nitrides with conductive carbon may relieve these issues.However,little is known about the influence of nitrogen(N)configurations on the interactions between carbon and C_(3)N_(4),which is fundamentally critical for guiding the precise design of advanced C_(3)N_(4)-related electrodes.Herein,highly crystalline C_(3)N_(4)(poly(triazine imide),PTI)based all-carbon composites were developed by molten salt strategy.More importantly,the vital role of pyrrolic-N for enhancing charge transfer and boosting Na+storage of C_(3)N_(4)-based composites,which was confirmed by both theoretical and experimental evidence,was spot-highlighted for the first time.By elaborately controlling the salt composition,the composite with high pyrrolic-N and minimized graphitic-N content was obtained.Profiting from the formation of highly crystalline PTI and electrochemically favorable pyrrolic-N configurations,the composite delivered an unusual reverse growth and record-level cycling stability even after 5000 cycles along with high reversible capacity and outstanding full-cell capacity retention.This work broadens the energy storage applications of C_(3)N_(4) and provides new prospects for the design of advanced all-carbon electrodes.展开更多
Efficient and low-cost recycling of spent lithium iron phosphate(LiFePO_(4),LFP)batteries has become an inevitable trend.In this study,an integrated closed-loop recycling strategy including isomorphic substitution lea...Efficient and low-cost recycling of spent lithium iron phosphate(LiFePO_(4),LFP)batteries has become an inevitable trend.In this study,an integrated closed-loop recycling strategy including isomorphic substitution leaching and solvent extraction process for spent LFP was proposed.An inexpensive FeCl_(3)was used as leaching agent to directly substitute Fe^(2+)from LFP.99%of Li can be rapidly leached in just 30 min,accompanied by 98%of FePO_(4)precipitated in lixivium.The tri-n-butyl phosphate(TBP)-sulfonated kerosene(SK)system was applied to extract Li from lixivium through a twelve-stage countercurrent process containing synchronous extraction and stepwise stripping of Li^(+)and Fe^(3+).80.81%of Li can be selectively enriched in stripping liquor containing 3.059 mol·L^(-1)of Li^(+)under optimal conditions.And the Fe stripping liquor was recovered for LFP re-leaching,of which,Fe^(2+)was oxidized to Fe^(3+)by appropriate H_(2)O_(2).Raffinate and lixivium were concentrated and entered into extraction process to accomplished closeloop recycling process.Overall,the results suggest that more than 99%of Li was recovered.FeCl_(3)holding in solution was directly regenerated without any pollutant emission.The sustainable mothed would be an alternative candidate for total element recycling of spent LFP batteries with industrial potential.展开更多
With the increasing popularity of new en ergy electric vehicles,the dema nd for lithium-ion batteries(LIBs)has been growing rapidly,which will produce a large number of spent LIBs.Therefore,recycling of spe nt LIBs ha...With the increasing popularity of new en ergy electric vehicles,the dema nd for lithium-ion batteries(LIBs)has been growing rapidly,which will produce a large number of spent LIBs.Therefore,recycling of spe nt LIBs has become an urge nt task to be solved,otherwise it will inevitably lead to serious environmental pollution.Herein,a unique recycling strategy is proposed to achieve the concurrent reuse of cathode and anode in the spent graphite/LiFePO_(4) batteries.Along with such recycling process,a unique cathode composed of recycled LFP/graphite(RLFPG)with cation/anion-co-storage ability is designed for new-type dual-ion battery(DIB).As a result,the recycle-derived DIB of Li/RLFPG is established with good electrochemical performance,such as an initial discharge capacity of 117.4 mA h g^(-1) at 25 mA g^(-1) and 78% capacity retention after 1000 cycles at 100 mA g^(-1).The working mechanism of Li/RLFPG DIB is also revealed via in situ X-ray diffraction and electrode kinetics studies.This work not only presents a farreaching significance for large-scale recycling of spent LIBs in the future,but also proposed a sustainable and econo mical method to design n ew-type sec on dary batteries as recycling of spe nt LIBs.展开更多
Lithium-ion batteries(LIBs)require separators with high performance and safety to meet the increasing demands for energy storage applications.Coating electrochemically inert ceramic materials on conventional polyolefi...Lithium-ion batteries(LIBs)require separators with high performance and safety to meet the increasing demands for energy storage applications.Coating electrochemically inert ceramic materials on conventional polyolefin separators can enhance stability but comes at the cost of increased weight and decreased capacity of the battery.Herein,a novel separator coated with lithium iron phosphate(LFP),an active cathode material,is developed via a simple and scalable process.The LFP-coated separator exhibits superior thermal stability,mechanical strength,electrolyte wettability,and ionic conductivity than the conventional polyethylene(PE)separator.Moreover,the LFP coating can actively participate in the electrochemical reaction during the charge-discharge process,thus enhancing the capacity of the battery.The results show that the LFP-coated separator can increase the cell capacity by 26%,and improve the rate capability by 29%at 4 C compared with the conventional PE separator.The LFP-coated separator exhibits only 1.1%thermal shrinkage at 140°C,a temperature even above the melting point of PE.This work introduces a new strategy for designing separators with dual functions for the next-generation LIBs with improved performance and safety.展开更多
The requirement of energy-storage equipment needs to develop the lithium ion battery(LIB) with high electrochemical performance. The surface modification of commercial LiFePO_4(LFP) by utilizing zeolitic imidazolate f...The requirement of energy-storage equipment needs to develop the lithium ion battery(LIB) with high electrochemical performance. The surface modification of commercial LiFePO_4(LFP) by utilizing zeolitic imidazolate frameworks-8(ZIF-8) offers new possibilities for commercial LFP with high electrochemical performances.In this work, the carbonized ZIF-8(C_(ZIF-8)) was coated on the surface of LFP particles by the in situ growth and carbonization of ZIF-8. Transmission electron microscopy indicates that there is an approximate 10 nm coating layer with metal zinc and graphite-like carbon on the surface of LFP/C_(ZIF-8) sample. The N_2 adsorption and desorptionisotherm suggests that the coating layer has uniform and simple connecting mesopores. As cathode material, LFP/C_(ZIF-8) cathode-active material delivers a discharge specific capacity of 159.3 m Ah g^(-1) at 0.1 C and a discharge specific energy of 141.7 m Wh g^(-1) after 200 cycles at 5.0 C(the retention rate is approximate 99%). These results are attributed to the synergy improvement of the conductivity,the lithium ion diffusion coefficient, and the degree of freedom for volume change of LFP/C_(ZIF-8) cathode. This work will contribute to the improvement of the cathode materials of commercial LIB.展开更多
基金supported by the National Natural Science Foundation of China(51834008,52022109,52274307,and 21804319)National Key Research and Development Program of China(2021YFC2901100)+1 种基金Science Foundation of China University of Petroleum,Beijing(2462022QZDX008,2462021QNX2010,2462020YXZZ019 and 2462020YXZZ016)State Key Laboratory of Heavy Oil Processing(HON-KFKT2022-10).
文摘A green environmental protection and enhanced leaching process was proposed to recover all elements from spent lithium iron phosphate(LiFePO_(4)) lithium batteries.In order to reduce the influence of Al impurity in the recovery process,NaOH was used to remove impurity.After impurity removal,the spent LiFePO_(4) cathode material was used as raw material under the H_(2)SO_(4) system,and the pressure oxidation leaching process was adopted to achieve the preferential leaching of lithium.The E-pH diagram of the Fe-P-Al-H_(2)O system can determine the stable region of each element in the recovery process of spent LiFePO_(4)Li-batteries.Under the optimal conditions(500 r·min^(-1),15 h,363.15 K,0.4 MPa,the liquid-solid ratio was 4:1 ml·g^(-1)and the acid-material ratio was 0.29),the leaching rate of Li was 99.24%,Fe,Al,and Ti were 0.10%,2.07%,and 0.03%,respectively.The Fe and P were precipitated and recovered as FePO_(4)·2H_(2)O.The kinetic analysis shows that the process of high-pressure acid leaching of spent LiFePO_(4) materials depends on the surface chemical reaction.Through the life cycle assessment(LCA)of the spent LiFePO_(4) whole recovery process,eight midpoint impact categories were selected to assess the impact of recovery process.The results can provide basic environmental information on production process for recycling industry.
基金supported by the National Natural Science Foundation of China(51904059)Applied Basic Research Program of Liaoning(2022JH2/101300200)+1 种基金Guangdong Basic and Applied Basic Research Foundation(2022A1515140188)Fundamental Research Funds for the Central Universities(N_(2)002005,N_(2)125004,N_(2)225044)。
文摘Carbon nitrides with two-dimensional layered structures and high theoretical capacities are attractive as anode materials for sodium-ion batteries while their low crystallinity and insufficient structural stability strongly restrict their practical applications.Coupling carbon nitrides with conductive carbon may relieve these issues.However,little is known about the influence of nitrogen(N)configurations on the interactions between carbon and C_(3)N_(4),which is fundamentally critical for guiding the precise design of advanced C_(3)N_(4)-related electrodes.Herein,highly crystalline C_(3)N_(4)(poly(triazine imide),PTI)based all-carbon composites were developed by molten salt strategy.More importantly,the vital role of pyrrolic-N for enhancing charge transfer and boosting Na+storage of C_(3)N_(4)-based composites,which was confirmed by both theoretical and experimental evidence,was spot-highlighted for the first time.By elaborately controlling the salt composition,the composite with high pyrrolic-N and minimized graphitic-N content was obtained.Profiting from the formation of highly crystalline PTI and electrochemically favorable pyrrolic-N configurations,the composite delivered an unusual reverse growth and record-level cycling stability even after 5000 cycles along with high reversible capacity and outstanding full-cell capacity retention.This work broadens the energy storage applications of C_(3)N_(4) and provides new prospects for the design of advanced all-carbon electrodes.
基金financially supported by the National Natural Science Foundation of China(U1707601)project of Youth Innovation Promotion Association,Chinese Academy of Sciences(2021430)+1 种基金project of Innovation Academy for Green Manufacture,Chinese Academy of Sciences(IAGM2020C26)project of Bureau of International Cooperation,Chinese Academy of Sciences(122363KYSB20190033)。
文摘Efficient and low-cost recycling of spent lithium iron phosphate(LiFePO_(4),LFP)batteries has become an inevitable trend.In this study,an integrated closed-loop recycling strategy including isomorphic substitution leaching and solvent extraction process for spent LFP was proposed.An inexpensive FeCl_(3)was used as leaching agent to directly substitute Fe^(2+)from LFP.99%of Li can be rapidly leached in just 30 min,accompanied by 98%of FePO_(4)precipitated in lixivium.The tri-n-butyl phosphate(TBP)-sulfonated kerosene(SK)system was applied to extract Li from lixivium through a twelve-stage countercurrent process containing synchronous extraction and stepwise stripping of Li^(+)and Fe^(3+).80.81%of Li can be selectively enriched in stripping liquor containing 3.059 mol·L^(-1)of Li^(+)under optimal conditions.And the Fe stripping liquor was recovered for LFP re-leaching,of which,Fe^(2+)was oxidized to Fe^(3+)by appropriate H_(2)O_(2).Raffinate and lixivium were concentrated and entered into extraction process to accomplished closeloop recycling process.Overall,the results suggest that more than 99%of Li was recovered.FeCl_(3)holding in solution was directly regenerated without any pollutant emission.The sustainable mothed would be an alternative candidate for total element recycling of spent LFP batteries with industrial potential.
基金support from the National Natural Science Foundation of China(No.91963118)the Science Technology Program of Jilin Province(No.20200201066JC)the 111 Project(No.B13013).
文摘With the increasing popularity of new en ergy electric vehicles,the dema nd for lithium-ion batteries(LIBs)has been growing rapidly,which will produce a large number of spent LIBs.Therefore,recycling of spe nt LIBs has become an urge nt task to be solved,otherwise it will inevitably lead to serious environmental pollution.Herein,a unique recycling strategy is proposed to achieve the concurrent reuse of cathode and anode in the spent graphite/LiFePO_(4) batteries.Along with such recycling process,a unique cathode composed of recycled LFP/graphite(RLFPG)with cation/anion-co-storage ability is designed for new-type dual-ion battery(DIB).As a result,the recycle-derived DIB of Li/RLFPG is established with good electrochemical performance,such as an initial discharge capacity of 117.4 mA h g^(-1) at 25 mA g^(-1) and 78% capacity retention after 1000 cycles at 100 mA g^(-1).The working mechanism of Li/RLFPG DIB is also revealed via in situ X-ray diffraction and electrode kinetics studies.This work not only presents a farreaching significance for large-scale recycling of spent LIBs in the future,but also proposed a sustainable and econo mical method to design n ew-type sec on dary batteries as recycling of spe nt LIBs.
基金supported by the Natural Science foundation of China(51972043)the Sichuan-Hong Kong Collaborative Research Fund(2021YFH0184)the Natural Science foundation of Sichuan Province(2023NSFSC0417)。
文摘Lithium-ion batteries(LIBs)require separators with high performance and safety to meet the increasing demands for energy storage applications.Coating electrochemically inert ceramic materials on conventional polyolefin separators can enhance stability but comes at the cost of increased weight and decreased capacity of the battery.Herein,a novel separator coated with lithium iron phosphate(LFP),an active cathode material,is developed via a simple and scalable process.The LFP-coated separator exhibits superior thermal stability,mechanical strength,electrolyte wettability,and ionic conductivity than the conventional polyethylene(PE)separator.Moreover,the LFP coating can actively participate in the electrochemical reaction during the charge-discharge process,thus enhancing the capacity of the battery.The results show that the LFP-coated separator can increase the cell capacity by 26%,and improve the rate capability by 29%at 4 C compared with the conventional PE separator.The LFP-coated separator exhibits only 1.1%thermal shrinkage at 140°C,a temperature even above the melting point of PE.This work introduces a new strategy for designing separators with dual functions for the next-generation LIBs with improved performance and safety.
基金supported by the Scientific and Technological Development Project of the Beijing Education Committee(No.KZ201710005009)
文摘The requirement of energy-storage equipment needs to develop the lithium ion battery(LIB) with high electrochemical performance. The surface modification of commercial LiFePO_4(LFP) by utilizing zeolitic imidazolate frameworks-8(ZIF-8) offers new possibilities for commercial LFP with high electrochemical performances.In this work, the carbonized ZIF-8(C_(ZIF-8)) was coated on the surface of LFP particles by the in situ growth and carbonization of ZIF-8. Transmission electron microscopy indicates that there is an approximate 10 nm coating layer with metal zinc and graphite-like carbon on the surface of LFP/C_(ZIF-8) sample. The N_2 adsorption and desorptionisotherm suggests that the coating layer has uniform and simple connecting mesopores. As cathode material, LFP/C_(ZIF-8) cathode-active material delivers a discharge specific capacity of 159.3 m Ah g^(-1) at 0.1 C and a discharge specific energy of 141.7 m Wh g^(-1) after 200 cycles at 5.0 C(the retention rate is approximate 99%). These results are attributed to the synergy improvement of the conductivity,the lithium ion diffusion coefficient, and the degree of freedom for volume change of LFP/C_(ZIF-8) cathode. This work will contribute to the improvement of the cathode materials of commercial LIB.
