Current and deformation induced by voltage in the single LiNi_0.8Co_0.1Mn_0.1O₂ particle from atomic force microscopy technique and phase field simulation

Abstract One of the key factors affecting lithium-ion battery electrode materials’ efficiency is the process of lithiation and delithiation. Studies of the electrochemical behavior of Ni-rich active electrode materials at the nanoscale have largely been focused on macroscopic measurements, but few have investigated the intrinsic microscopic mechanism underlying their failure. In this paper, lithium-ion diffusion current and surface deformation of single LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) nanoparticles under external electric fields were measured by atomic force microscopy (AFM) techniques. Then, the current and deformation of NCM811 single particle under the applied voltage were simulated by phase field method to analyze electrochemical behaviors of the particle from experiments based on the electrochemical-mechanical coupled model. The simulation results revealed that the change of lithium-ion concentration and stress in particles are the factors leading to the evolution of current and deformation under applied voltage observed by AFM.