Cao Yue, Kang Guohuang, Duan Jiachao, Yin Rui, Meng Ying, Yu Kuang, Kang Feiyu, Cao Yidan
Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
ACS Nano. 2025 Oct 7;19(39):34745-34756. doi: 10.1021/acsnano.5c09514. Epub 2025 Sep 22.
Manipulating the solvation environment of lithium ions (Li) in liquid electrolytes is crucial for achieving a stable solid electrolyte interphase (SEI) layer on lithium metal anodes. In this work, we report a method to regulate the Li solvation environment in ester-based electrolytes by incorporating lithium nitrate (LiNO) nanoparticles as an additive. The dipole-dipole interactions at the LiNO particle/electrolyte interface result in ordered aggregation of solvent molecules on the surface of LiNO particles, forming a molecular confinement layer that drives the formation of a weak Li solvation environment. This enables Li to bind more readily with anions, facilitates rapid Li conduction, and promotes an inorganic-rich SEI. Electrochemical tests show that such changes induced by LiNO nanoparticles significantly enhance the Coulombic efficiency, reduce lithium nucleation overpotential, suppress lithium dendrite growth, and extend the cycle life of anode-free cells. Besides, with 6000 ppm of HO in the electrolyte, cells achieve stable cycling for over 200 cycles with a capacity retention of 71.21%. These findings provide insights into solvent/ion regulation at solid/liquid interfaces in advanced electrolytes.
控制液体电解质中锂离子（Li）的溶剂化环境对于在锂金属阳极上实现稳定的固体电解质界面（SEI）层至关重要。在这项工作中，我们报告了一种通过加入硝酸锂（LiNO₃）纳米颗粒作为添加剂来调节酯基电解质中Li溶剂化环境的方法。LiNO₃颗粒/电解质界面处的偶极-偶极相互作用导致溶剂分子在LiNO₃颗粒表面有序聚集，形成一个分子限制层，从而促使形成弱Li溶剂化环境。这使得Li能够更容易地与阴离子结合，促进Li的快速传导，并促进富含无机物的SEI的形成。电化学测试表明，LiNO₃纳米颗粒引起的这些变化显著提高了库仑效率，降低了锂成核过电位，抑制了锂枝晶生长，并延长了无阳极电池的循环寿命。此外，在电解质中加入6000 ppm的H₂O时，电池可实现超过200次循环的稳定循环，容量保持率为71.21%。这些发现为先进电解质中固/液界面处的溶剂/离子调控提供了见解。
