3D Structure Analysis for Understanding of Li Electrodeposition and Dissolution Mechanism

Li metal was electrodeposited and electrochemically dissolved on an ultra-micro-electrode to model the transition of morphology and three-dimensional structure of a Li metal electrode during cycles. The first electrodeposition produced a uniform and dense column structure, but solid electrolyte interphase (SEI) remained on the electrode during the next electrochemical dissolution. The accumulation of the SEI residue obstructs the uniform electrodeposition of Li metal in the following cycles and increases resistance, accelerating the degradation of the electrode and causing the isolated Li metal to form the “dead lithium.”