华南理工大学杜丽团队报道了一种用于极快充电和长日历寿命硅基锂离子电池的微观非均相胶体电解质。相关研究成果于2024年7月20日发表于国际一流学术期刊《德国应用化学》。

快速充电能力和日历寿命是可充电电池的关键指标，特别是在硅基电池中，硅基电池容易受到缓慢的Li⁺脱溶剂动力学和HF引起的腐蚀。现有的电解质无法同时应对这两个关键挑战。

该文中，研究人员报告了一种用于极快充电和长寿命硅基锂离子电池的，微观异质共价有机纳米片（CON）胶体电解质。理论计算和拉曼光谱揭示了多尺度非共价相互作用的基本机制，其中涉及介观CON衰减微观Li⁺-溶剂配位，从而加速Li⁺去溶剂化动力学。这种电解质设计使全电池在8C（83.1%充电状态）和10C（81.3%充电状态）下都具有极快的充电能力。

值得注意的是，胶体电解质在10C下表现出破纪录的循环性能（400次循环后容量保持率为92.39%）。此外，得益于介孔CON对HF和水的强大吸附能力，观察到全电池的日历寿命有了显著提高。

该研究强调了微观异质胶体电解质，在提高硅基锂离子电池快速充电能力和日历寿命方面的作用。研究工作为具有多尺度相互作用的电解质设计提供了新的视角，为在恶劣环境下运行的碱离子/金属电池的开发提供了有见地的指导。

附：英文原文

Title: A Microscopically Heterogeneous Colloid Electrolyte for Extremely Fast-Charging and Long-Calendar-Life Silicon-Based Lithium-Ion Batteries

Author: Weifeng Zhang, Wenwu Zou, Guoxing Jiang, Shengguang Qi, Siyuan Peng, Huiyu Song, Zhiming Cui, Zhenxing Liang, Li Du

Issue&Volume: 2024-07-20

Abstract: Fast-charging capability and calendar life are critical metrics in rechargeable batteries, especially in silicon-based batteries that are susceptible to sluggish Li+ desolvation kinetics and HF-induced corrosion. No existing electrolyte simultaneously tackles both these pivotal challenges. Here we report a microscopically heterogeneous covalent organic nanosheet (CON) colloid electrolyte for extremely fast-charging and long-calendar-life Si-based lithium-ion batteries. Theoretical calculations and operando Raman spectroscopy reveal the fundamental mechanism of the multiscale noncovalent interaction, which involves the mesoscopic CON attenuating the microscopic Li+-solvent coordination, thereby expediting the Li+ desolvation kinetics. This electrolyte design enables extremely fast-charging capabilities of the full cell, both at 8C (83.1% state of charge) and 10C (81.3% state of charge). Remarkably, the colloid electrolyte demonstrates record-breaking cycling performance at 10C (capacity retention of 92.39% after 400 cycles). Moreover, benefiting from the robust adsorption capability of mesoporous CON towards HF and water, a notable improvement is observed in the calendar life of the full cell. This study highlights the role of microscopically heterogeneous colloid electrolytes in enhancing the fast-charging capability and calendar life of Si-based Li-ion batteries. Our work offers fresh perspectives on electrolyte design with multiscale interactions, providing insightful guidance for the development of alkali-ion/metal batteries operating under harsh environments.

DOI: 10.1002/anie.202410046

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202410046