An Interlayer Containing Dissociated LiNO<sub>3</sub> with Fast Release Speed for Stable Lithium Metal Batteries with 400 Wh kg<sup>−1</sup> Energy Density
Huicong Yang, Qingyun Liu, Yaozu Wang, Zhuoting Ma, Pei Tang, Xiaoyin Zhang, Hui–Ming Cheng, Zhenhua Sun, Feng Li
Abstract
Abstract Lithium metal is an ideal electrode material for future rechargeable batteries. However, dendrite formation and unstable solid electrolyte interphase film lead to safety concerns and poor Coulombic efficiency (CE). LiNO 3 significantly improves the performance of the lithium metal anode in ester electrolytes but its use is restricted by low solubility. To increase the content of LiNO 3 in the cell, a poly‐(vinyl carbonate) organogel interlayer containing dissociated LiNO 3 (LNO‐PVC) is placed between the cathode and anode. The dissociated LiNO 3 effectively increases the LiNO 3 ‐release rate and compensates for the LiNO 3 consumed in ester electrolytes during cycling. Via this interlayer, the performance of the lithium metal anode is significantly improved. The average CE of a Li‐Cu cell reaches 98.6% at 0.5 mA cm −2 ‐1 h and 98.5% at 1 mA cm −2 ‐1 h for 300 cycles. Also, a Li||NCM811 pouch cell with LNO‐PVC interlayer can also reach a 400 Wh kg −1 energy density with a cycling life of 65 cycles. This strategy sheds light on the effect of the state of this salt on its release/dissolution kinetics, which is determined by the interactions between the salt and host material.