Single-crystal Ni-rich cathodes are a promising candidate for high-energy lithium-ion batteries due to their higher structural and cycling stability than polycrystalline materials.However,the phase evolution and capac...Single-crystal Ni-rich cathodes are a promising candidate for high-energy lithium-ion batteries due to their higher structural and cycling stability than polycrystalline materials.However,the phase evolution and capacity degradation of these single-crystal cathodes during continuous lithation/delithation cycling remains unclear.Understanding the mapping relationship between the macroscopic electrochemical properties and the material physicochemical properties is crucial.Here,we investigate the correlation between the physical-chemical characteristics,phase transition,and capacity decay using capacity differential curve feature identification and in-situ X-ray spectroscopic imaging.We systematically clarify the dominant mechanism of phase evolution in aging cycling.Appropriately high cut-off voltages can mitigate the slow kinetic and electrochemical properties of single-crystal cathodes.We also find that second-order differential capacity discharge characteristic curves can be used to identify the crystal structure disorder of Ni-rich cathodes.These findings constitute a step forward in elucidating the correlation between the electrochemical extrinsic properties and the physicochemical intrinsic properties and provide new perspectives for failure analysis of layered electrode materials.展开更多
The existing recycling and regeneration technologies have problems,such as poor regeneration effect and low added value of products for lithium(Li)-ion battery cathode materials with a low state of health.In this work...The existing recycling and regeneration technologies have problems,such as poor regeneration effect and low added value of products for lithium(Li)-ion battery cathode materials with a low state of health.In this work,a targeted Li replenishment repair technology is proposed to improve the discharge-specific capacity and cycling stability of the repaired LiCoO_(2) cathode materials.Compared with the spent cathode material with>50%Li deficiency,the Li/Co molar ratio of the regenerated LiCoO_(2) cathode is>0.9,which completely removes the Co_(3)O_(4) impurity phase formed by the decomposition of LixCoO_(2) in the failed cathode material after repair.The repaired LiCoO_(2) cathode mater-ials exhibit better cycling stability,lower electrochemical impedance,and faster Li^(+)diffusion than the commercial materials at both 1 and 10 C.Meanwhile,Li_(1.05)CoO_(2) cathodes have higher Li replenishment efficiency and cycling stability.The energy consumption and greenhouse gas emissions of LiCoO_(2) cathodes produced by this repair method are significantly reduced compared to those using pyrometallurgical and hydro-metallurgical recycling processes.展开更多
Directly repairing end-of-life lithium-ion battery cathodes poses significant chal-lenges due to the diverse compositions of the wastes.Here,we propose a water-facilitated targeted repair strategy applicable to variou...Directly repairing end-of-life lithium-ion battery cathodes poses significant chal-lenges due to the diverse compositions of the wastes.Here,we propose a water-facilitated targeted repair strategy applicable to various end-of-life batches and cathodes.The process involves initiating structural repair and reconstruct-ing particle morphology in degraded LiMn_(2)O_(4)(LMO)through an additional thermal drive post-ambient water remanganization,achieving elemental repair.Compared to solid-phase repair,the resulting LMO material exhibits superior electrochemical and kinetic characteristics.The theoretical analysis highlights the impact of Mn defects on the structural stability and electron transfer rate of degraded materials.The propensity of Mn ions to diffuse within the Mn layer,specifically occupying the Mn 16d site instead of the Li 8a site,theoretically sup-ports the feasibility of ambient water remanganization.Moreover,this method proves effective in the relithiation of degraded layered cathode materials,yielding single crystals.By combining low energy consumption,environmental friendli-ness,and recyclability,our study proposes a sustainable approach to utilizing spent batteries.This strategy holds the potential to enable the industrial direct repair of deteriorated cathode materials.展开更多
A way of directly repairing spent lithium-ion battery cathode materials is needed in response to environmental pollution and resource depletion.In this work,we report a green repair method involving coupled mechano-ch...A way of directly repairing spent lithium-ion battery cathode materials is needed in response to environmental pollution and resource depletion.In this work,we report a green repair method involving coupled mechano-chemistry and solid-state reactions for spent lithium-ion batteries.During the ball-milling repair process,an added manganese source enters into the degraded LiMn_(2)O_(4)(LMO)crystal structure in order to fill the Mn vacancies formed by Mn deficiency due to the Jahn–Teller effect,thereby repairing the LMO's chemical composition.An added carbon source acts not only as a lubricant but also as a conductor to improve the material's electrical conductivity.Meanwhile,mechanical force reduces the crystal size of the LMO particles,increasing the amount of active sites for electrochemical reactions.Jahn–Teller distortion is successfully suppressed by cation disorder in the LMO material.The cycling stability and rate performance of the repaired cathode material are thereby greatly improved,with the discharge specific capacity being more than twice that of commercial LMO.The proposed solid-state mechanochemical in situ repair process,which is safe for the environment and simple to use,may be extended to the repair of other waste materials without consuming highly acidic or alkaline chemical reagents.展开更多
文摘Single-crystal Ni-rich cathodes are a promising candidate for high-energy lithium-ion batteries due to their higher structural and cycling stability than polycrystalline materials.However,the phase evolution and capacity degradation of these single-crystal cathodes during continuous lithation/delithation cycling remains unclear.Understanding the mapping relationship between the macroscopic electrochemical properties and the material physicochemical properties is crucial.Here,we investigate the correlation between the physical-chemical characteristics,phase transition,and capacity decay using capacity differential curve feature identification and in-situ X-ray spectroscopic imaging.We systematically clarify the dominant mechanism of phase evolution in aging cycling.Appropriately high cut-off voltages can mitigate the slow kinetic and electrochemical properties of single-crystal cathodes.We also find that second-order differential capacity discharge characteristic curves can be used to identify the crystal structure disorder of Ni-rich cathodes.These findings constitute a step forward in elucidating the correlation between the electrochemical extrinsic properties and the physicochemical intrinsic properties and provide new perspectives for failure analysis of layered electrode materials.
基金supported by the National Natural Science Foundation of China (Nos. 51972030 and 51772030)the S&T Major Project of Inner Mongolia Autonomous Region in China (No. 2020ZD0018)+1 种基金the Beijing Outstanding Young Scientists Program (No. BJJWZYJH01201910007023)the Guangdong Key Laboratory of Battery Safety (No. 2019B121203008)
文摘The existing recycling and regeneration technologies have problems,such as poor regeneration effect and low added value of products for lithium(Li)-ion battery cathode materials with a low state of health.In this work,a targeted Li replenishment repair technology is proposed to improve the discharge-specific capacity and cycling stability of the repaired LiCoO_(2) cathode materials.Compared with the spent cathode material with>50%Li deficiency,the Li/Co molar ratio of the regenerated LiCoO_(2) cathode is>0.9,which completely removes the Co_(3)O_(4) impurity phase formed by the decomposition of LixCoO_(2) in the failed cathode material after repair.The repaired LiCoO_(2) cathode mater-ials exhibit better cycling stability,lower electrochemical impedance,and faster Li^(+)diffusion than the commercial materials at both 1 and 10 C.Meanwhile,Li_(1.05)CoO_(2) cathodes have higher Li replenishment efficiency and cycling stability.The energy consumption and greenhouse gas emissions of LiCoO_(2) cathodes produced by this repair method are significantly reduced compared to those using pyrometallurgical and hydro-metallurgical recycling processes.
基金Beijing Natural Science Foundation,Grant/Award Number:Z220021National Key R&D Program of China,Grant/Award Number:2022YFB3305400+3 种基金National Natural Science Foundation of China,Grant/Award Numbers:22202011,52102207Joint Funds of the National Natural Science Foundation of China,Grant/Award Number:U2130204Beijing Outstanding Young Scientists Program,Grant/Award Number:BJJWZYJH01201910007023Shandong Provincial Natural Science Foundation,Grant/Award Number:ZR2022QB056。
文摘Directly repairing end-of-life lithium-ion battery cathodes poses significant chal-lenges due to the diverse compositions of the wastes.Here,we propose a water-facilitated targeted repair strategy applicable to various end-of-life batches and cathodes.The process involves initiating structural repair and reconstruct-ing particle morphology in degraded LiMn_(2)O_(4)(LMO)through an additional thermal drive post-ambient water remanganization,achieving elemental repair.Compared to solid-phase repair,the resulting LMO material exhibits superior electrochemical and kinetic characteristics.The theoretical analysis highlights the impact of Mn defects on the structural stability and electron transfer rate of degraded materials.The propensity of Mn ions to diffuse within the Mn layer,specifically occupying the Mn 16d site instead of the Li 8a site,theoretically sup-ports the feasibility of ambient water remanganization.Moreover,this method proves effective in the relithiation of degraded layered cathode materials,yielding single crystals.By combining low energy consumption,environmental friendli-ness,and recyclability,our study proposes a sustainable approach to utilizing spent batteries.This strategy holds the potential to enable the industrial direct repair of deteriorated cathode materials.
基金This work was supported by the National Natural Science Foundation of China(51972030,52102207)Beijing Natural Science Foundation(Z220021)+2 种基金the National Key R&D Program of China(2021YFB3800300)the Joint Funds of the National Natural Science Foundation of China(U2130204)Beijing Outstanding Young Sci-entists Program(BJJWZYJH01201910007023).
文摘A way of directly repairing spent lithium-ion battery cathode materials is needed in response to environmental pollution and resource depletion.In this work,we report a green repair method involving coupled mechano-chemistry and solid-state reactions for spent lithium-ion batteries.During the ball-milling repair process,an added manganese source enters into the degraded LiMn_(2)O_(4)(LMO)crystal structure in order to fill the Mn vacancies formed by Mn deficiency due to the Jahn–Teller effect,thereby repairing the LMO's chemical composition.An added carbon source acts not only as a lubricant but also as a conductor to improve the material's electrical conductivity.Meanwhile,mechanical force reduces the crystal size of the LMO particles,increasing the amount of active sites for electrochemical reactions.Jahn–Teller distortion is successfully suppressed by cation disorder in the LMO material.The cycling stability and rate performance of the repaired cathode material are thereby greatly improved,with the discharge specific capacity being more than twice that of commercial LMO.The proposed solid-state mechanochemical in situ repair process,which is safe for the environment and simple to use,may be extended to the repair of other waste materials without consuming highly acidic or alkaline chemical reagents.
