Innovative Anode Design to Enhance Both Volumetric and Gravimetric Energy Densities of LiCoO<sub>2</sub>||Graphite Pouch Cells
Yidan Zhang, Hua Wang, Zezhuo Li, Zezhuo Li, Xiaoyu Ge, Kai Huang, Jia‐Qi Huang, Ling Huang, Zhen Li, Zhen Li, Yunhui Huang
Abstract
Abstract The ratio of the anode (negative electrode) and cathode (positive electrode) areal capacities (N/P ratio), is an important parameter for Lithium‐ion batteries. Considering the manufacturing tolerance and battery safety, almost all of the batteries keep the N/P ratio > 1. Deviating from this ratio can lead to lithium precipitation on the anode surface, which poses significant risks. Here, by using a gradient structured graphite (Gr) anode, a new design concept is proposed that the N/P ratio could be less than 1, which can effectively achieve higher energy density without sacrificing the battery safety. This is achieved by incorporating a small quantity of silver (Ag) nanoparticles into the bottom layer of the anode (Gr‐Ag x ), which effectively modulates the concentration polarization of lithium ions along the thickness of the electrode. Moreover, the volumetric energy density of 4 Ah LiCoO 2 ||Gr‐Ag 0.5 (N/P = 0.8) pouch cell increases by 14.5% compared with LiCoO 2 ||Gr (N/P = 1.1). Furthermore, the universal applicability and efficacy of the N/P < 1 design paradigm in LiFePO 4 ||Gr cells are validated.