Integrated rocksalt-polyanion cathodes(DRXPS)are promising candidates for next-generation lithium-ion battery cathode materials that combine high energy density,stable cycling performance,and reduced reliance on Co an...Integrated rocksalt-polyanion cathodes(DRXPS)are promising candidates for next-generation lithium-ion battery cathode materials that combine high energy density,stable cycling performance,and reduced reliance on Co and Ni.In this work,we investigated Li_(3)Mn_(1.6)P_(0.4)O_(5.4)F_(0.6),a new DRXPS cathode with fluoride incorporation.A pure spinel phase was formed and a discharge capacity retention of 84%was achieved after 200 cycles between 1.5 and 4.8 V versus Li/Li^(+).In comparison,the similarly synthesized Li_(3)Mn_(1.6)Nb_(0.4)O_(5.4)F_(0.6),in which all P^(5+)was substituted by Nb^(5+)while maintaining the same stoichiometry for all other elements,crystallized in a disordered rocksalt structure,and exhibited inferior capacity retention and rate capability than the P^(5+)counterpart.Our findings expand the compositional space of DRXPS to include F^(−),justify the viability of integrating polyanion groups in rocksalt-type cathodes,and highlight the superiority of P^(5+)as a cation charge compensator compared to the commonly used Nb^(5+).This work thereby advances the design of robust,high-performance cathode materials for sustainable batteries.展开更多
基金sponsored by Tsinghua-Toyota Joint Research Fund.This study used resources of 18-ID and 23-ID-2 of the National Synchrotron Light Source II,a U.S.Department of Energy(DOE)Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No.DESC0012704.
文摘Integrated rocksalt-polyanion cathodes(DRXPS)are promising candidates for next-generation lithium-ion battery cathode materials that combine high energy density,stable cycling performance,and reduced reliance on Co and Ni.In this work,we investigated Li_(3)Mn_(1.6)P_(0.4)O_(5.4)F_(0.6),a new DRXPS cathode with fluoride incorporation.A pure spinel phase was formed and a discharge capacity retention of 84%was achieved after 200 cycles between 1.5 and 4.8 V versus Li/Li^(+).In comparison,the similarly synthesized Li_(3)Mn_(1.6)Nb_(0.4)O_(5.4)F_(0.6),in which all P^(5+)was substituted by Nb^(5+)while maintaining the same stoichiometry for all other elements,crystallized in a disordered rocksalt structure,and exhibited inferior capacity retention and rate capability than the P^(5+)counterpart.Our findings expand the compositional space of DRXPS to include F^(−),justify the viability of integrating polyanion groups in rocksalt-type cathodes,and highlight the superiority of P^(5+)as a cation charge compensator compared to the commonly used Nb^(5+).This work thereby advances the design of robust,high-performance cathode materials for sustainable batteries.
