Challenges in Application of Ni-Rich Layered Cathodes in All-Solid-State Lithium Batteries

All-solid-state batteries (ASSBs) are among the most promising next-generation battery candidates owing to their high energy density and safe operation, both of which are superior to those of lithium-ion batteries (LIBs). Application of Ni-rich layered cathodes in ASSBs is having the most attention due to their high energy densities, yet the consequence of application has not discovered thoroughly. This study evaluates the effects of the chemical composition of Ni-rich cathode materials on their electrochemical performance and elucidates the degradation mechanism in ASSBs featuring sulfide solid electrolyte. With increasing Ni content, the long Li+ diffusion pathway originating from the particle morphology more affected adversely the reversible capacity during the initial cycles. In addition, microcracks caused by anisotropic volume changes and interfacial reaction between the cathode and solid electrolyte degrade battery performances. Thus, modifying the morphology of the cathode material is a key challenge to improve the battery performances and develop high-energy-density ASSBs with Ni-rich layered cathodes. References Y.-K. Sun, ACS Energy Lett. 2020, 5, 3221-3223 S. H. Jung, U. H. Kim, J. H. Kim, S. Jun, C. S. Yoon, Y. S. Jung and Y. -K. Sun, Adv. Energy Mater. 2020, 10, 1903360 H.-H. Ryu, K.-J. Park, C. S. Yoon and Y.-K. Sun, Chem. Mater. 2018, 30, 1155