摘要
Lithium-rich manganese-based cathodes(R-LNCM)are potential candidates for next-generation Li^(+)bat-teries.However,their practical applications have impeded by the substantial voltage attenuation on cy-cling.The irreversible evolution of oxygen triggers transition-metal(TM)migration and structural re-arrangements,resulting in the voltage decay.Herein,a linkage-functionalized modification approach to tackle these challenges.The strategy involves the synchronous formation of an amorphous CuO coating,inner spinel structure,and oxygen vacancies on the surface of R-LNCM microspheres,effectively stabi-lizing the lattice oxygen evolution and suppressing structural distortion.Importantly,this three-in-one surface engineering approach is characterized by its environment-friendly attributes,cost-efficiency and seamless scalability.The corresponding cathode delivers a high specific capacity 298.2 mAh g^(-1)with ini-tial coulombic efficiency(ICE)95.18%at 0.1 C.The voltage decay and the capacity retention rate are 1.70 mV cycle^(-1)and 90.5%after 200 cycles at 1 C.The density functional theory shows that the diffusion energy barrier of Li^(+)in Li_(2)MnO_(3)can be reduced by introducing vacancy.Moreover,the introduction of spinel structure in R-LNCM material improves the stability and diffusion ability of R-LNCM.Therefore,the novel insight and method have a potential to make a significantly contribution to the commercialization of R-LNCM for high energy density batteries.
基金
financially supported by the National Key Re-search and Development Program of China(No.2021YFB2400401).
