Intermolecular Interaction Adjustment for LiNO<sub>3</sub> Solubility Promotion toward High-Performance Li||NCM811 Batteries
Chong Xu, Shuang Liu, Sai Che, Guang Ma, Gong Cheng, Dongyuan Zhang, Junjie Fu, Ye Wang, Jiahao Yang, Yuci Tian, Yongpeng Cui, Weihua Chen, Yongfeng Li
Abstract
Incorporating lithium nitrate (LiNO 3 ) as a film-forming additive into carbonate-based electrolytes presents a promising strategy to enhance the stability of high-energy-density Li||NCM811 batteries. However, the small size of Li + and the high donor number (DN) of NO 3 – hinder the dissociation of LiNO 3, and its limited solubility (<800 ppm) in carbonate-based electrolytes poses significant challenges for practical application. To address this issue, we propose a “Small-Sized Carrier” strategy that enhances the solubility of LiNO 3 in carbonate solvents by modulating the intermolecular interactions within the solvent system. This approach employs vinylene carbonate (VC), a small molecule with moderate polarity, to enhance the dissolution of LiNO 3 without compromising the compatibility of the electrolyte with the lithium metal anode. The introduction of the “Small-Sized Carrier” additive system simultaneously enhances the stability of the electrode–electrolyte interfaces and optimizes the solvation structure of the electrolyte. As a result, the electrolyte developed through this strategy demonstrates outstanding electrochemical performance, with Li||NCM811 batteries achieving a capacity retention of 83.8% after 600 cycles. This work provides an insightful approach to designing advanced electrolytes tailored to high-energy-density lithium metal batteries (LMBs).