Li-rich layered oxide(LRLO)cathodes have been regarded as promising candidates for next-generation Li-ion batteries due to their exceptionally high energy density,which combines cationic and anionic redox activities.H...Li-rich layered oxide(LRLO)cathodes have been regarded as promising candidates for next-generation Li-ion batteries due to their exceptionally high energy density,which combines cationic and anionic redox activities.However,continuous voltage decay during cycling remains the primary obstacle for practical applications,which has yet to be fundamentally addressed.It is widely acknowledged that voltage decay originates from the irreversible migration of transition metal ions,which usually further exacerbates structural evolution and aggravates the irreversible oxygen redox reactions.Recently,constructing O2-type structure has been considered one of the most promising approaches for inhibiting voltage decay.In this review,the relationship between voltage decay and structural evolution is systematically elucidated.Strategies to suppress voltage decay are systematically summarized.Additionally,the design of O2-type structure and the corresponding mechanism of suppressing voltage decay are comprehensively discussed.Unfortunately,the reported O2-type LRLO cathodes still exhibit partially disordered structure with extended cycles.Herein,the factors that may cause the irreversible transition metal migrations in O2-type LRLO materials are also explored,while the perspectives and challenges for designing high-performance O2-type LRLO cathodes without voltage decay are proposed.展开更多
无水氟化铜(CuF_(2))有望成为下一代锂电池正极材料,其高比容量(528 mA h g^(−1))和高工作电压(3.55 V vs.Li/Li^(+))使得其能量密度高达1874 W h kg^(−1).然而,由于充电时铜的溶解,CuF_(2)正极容易失活,这限制了其发展.本研究采用氟化...无水氟化铜(CuF_(2))有望成为下一代锂电池正极材料,其高比容量(528 mA h g^(−1))和高工作电压(3.55 V vs.Li/Li^(+))使得其能量密度高达1874 W h kg^(−1).然而,由于充电时铜的溶解,CuF_(2)正极容易失活,这限制了其发展.本研究采用氟化高浓电解液抑制铜的溶解,从而实现了CuF_(2)正极的可逆循环.采用氟化高浓电解液后,CuF_(2)正极的容量在30次循环后仍保有228 mA h g^(−1),是使用传统碳酸酯类电解液的电池容量的近三倍.综上,本研究提出了一种电解质工程策略,可以实现CuF_(2)正极的可逆充放电.展开更多
基金funded by the National Natural Science Foundation of China(Grant Nos.22279092 and 5202780089).
文摘Li-rich layered oxide(LRLO)cathodes have been regarded as promising candidates for next-generation Li-ion batteries due to their exceptionally high energy density,which combines cationic and anionic redox activities.However,continuous voltage decay during cycling remains the primary obstacle for practical applications,which has yet to be fundamentally addressed.It is widely acknowledged that voltage decay originates from the irreversible migration of transition metal ions,which usually further exacerbates structural evolution and aggravates the irreversible oxygen redox reactions.Recently,constructing O2-type structure has been considered one of the most promising approaches for inhibiting voltage decay.In this review,the relationship between voltage decay and structural evolution is systematically elucidated.Strategies to suppress voltage decay are systematically summarized.Additionally,the design of O2-type structure and the corresponding mechanism of suppressing voltage decay are comprehensively discussed.Unfortunately,the reported O2-type LRLO cathodes still exhibit partially disordered structure with extended cycles.Herein,the factors that may cause the irreversible transition metal migrations in O2-type LRLO materials are also explored,while the perspectives and challenges for designing high-performance O2-type LRLO cathodes without voltage decay are proposed.
基金This work was supported by the Fundamental Research Funds for the Central Universities and the Institute of Carbon Neutrality of Tongji University.
文摘无水氟化铜(CuF_(2))有望成为下一代锂电池正极材料,其高比容量(528 mA h g^(−1))和高工作电压(3.55 V vs.Li/Li^(+))使得其能量密度高达1874 W h kg^(−1).然而,由于充电时铜的溶解,CuF_(2)正极容易失活,这限制了其发展.本研究采用氟化高浓电解液抑制铜的溶解,从而实现了CuF_(2)正极的可逆循环.采用氟化高浓电解液后,CuF_(2)正极的容量在30次循环后仍保有228 mA h g^(−1),是使用传统碳酸酯类电解液的电池容量的近三倍.综上,本研究提出了一种电解质工程策略,可以实现CuF_(2)正极的可逆充放电.
