Mitigating Particle Cracking and Surface Deterioration for Better Cycle Stability by Encapsulating NCM811 primary particles into LiBO2

Abstract

Nickel-rich layered cathode materials have drawn a lot of attention due to their much higher energy density and lower cost. However, there is still a challenge in long-term cycling stability for practical application. In this work, a modification strategy of encapsulation on primary particles of NCM811 is applied to improve the electrochemical performance of LiNi0.80Co0.10Mn0.10O2 (NCM811) by effecitively mitigating particle cracking and surface deterioration of NCM811. Compared with the general NCM811 (G0-811), the optimized NCM811 (O3-811) exhibites higher specific capacity and much improved cycle stability. After 800 cycles, the capacity retion of O3-811 is 91.8%, while the capacity of G0-811 fades rapidly in 430 cycles. Cross section SEM, EIS and DSC have been applied for futher abservation on the cycled O3-811 in comparison with G0-811. The results comfirm that the encapsulating NCM811 primary particles as well as secondary spheres into LiBO2 successfully improves the electrochemical performances and structure stability of NCM811, which is hopeful for commercial application.