The Electrolysis of Anti‐Perovskite Li<sub>2</sub>OHCl for Prelithiation of High‐Energy‐Density Batteries
Lulu Guo, Chen Xin, Jian Gao, Jianxun Zhu, Yiming Hu, Ying Zhang, Junpeng Li, Xiulin Fan, Yutao Li, Hong Li, Jieshan Qiu, Weidong Zhou
Abstract
Abstract Anti‐perovskite type Li 2 OHCl was previously studied as a solid‐state Li + conductor. Here, we report that the Li 2 OHCl can be electrolyzed at 3.3 V or 4.0 V, with the creation of O 2 /HCl gases and the release of 2 equiv. Li + via two different decomposition routes, depending on the acidity of electrolyte. In the electrolyte with trace acid, the Li 2 OHCl is oxidized at a constant voltage of 3.3 V. In neutral electrolyte, the oxidization of Li 2 OHCl starts at 4.0 V, but the produced HCl will increase the acidity of electrolyte and lead to a voltage drop to 3.3 V for the electrolysis of Li 2 OHCl. The electrolysis of Li 2 OHCl delivers a lithium releasing capacity as high as 810 mAh g −1 , with an equivalent Li‐deposition or Li‐intercalation on anode, making it a promising candidate as a Li reservoir for prelithiation of anode. Using Li 2 OHCl as the lithium source, silicon‐carbon (Si@C) composite anode can be effectively prelithiated. The full cells composed of LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) cathode and prelithiated Si@C anode exhibited increased capacities with the increment of prelithiation dosages.