The Electrolysis of Anti-Perovskite Li OHCl for Prelithiation of High-Energy-Density Batteries.

Anti-perovskite type Li OHCl was previously studied as a solid-state Li conductor. Here, we report that the Li OHCl can be electrolyzed at 3.3 V or 4.0 V, with the creation of O /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 OHCl is oxidized at a constant voltage of 3.3 V. In neutral electrolyte, the oxidization of Li 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 OHCl. The electrolysis of Li OHCl delivers a lithium releasing capacity as high as 810 mAh g , 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 OHCl as the lithium source, silicon-carbon (Si@C) composite anode can be effectively prelithiated. The full cells composed of LiNi Mn Co O (NMC811) cathode and prelithiated Si@C anode exhibited increased capacities with the increment of prelithiation dosages.