近日，英国剑桥大学Akshay Rao团队报道了石墨中的类雪崩插层与颗粒内关联。该研究于2026年7月29日发表在《自然》杂志上。

尽管石墨是锂离子电池中最广泛使用的负极材料，但其锂插层过程及相关动力学，尤其是稀相阶段，至今仍知之甚少。关于对称破缺相变如何在工况条件下连续发生，目前缺乏根本性的认识。

研究组利用原位光学显微镜，为石墨插层稀相阶段的离子插层动力学提供了统一图景，表明石墨颗粒会经历快速的局域化脱插–插层步进事件，导致微米尺度的区域在数秒内完成脱插–插层。这些现象类似于无序材料中发生的相变现象——“雪崩”，其特征是序参量因多个亚稳态之间的跳跃而发生阶跃变化。通过改进的随机场伊辛模型，研究组将雪崩与静态无序关联起来，后者扰乱了插层动力学。

该模型还能解释相之间看似连续的转变以及实验观测到的雪崩统计规律。最后，研究组开发了一种对雪崩事件序列进行时空分析的方法，揭示了显著的非均质连通性。该工作强调了局域静态无序在解释意料之外的相变行为中的作用，并为层状电池材料的研究提供了新的工具和概念。

附：英文原文

Title: Avalanche-like intercalation and intraparticle correlations in graphite

Author: Han, Jiho, Phillips, George S., Merryweather, Alice J., Lim, Juhwan, Schnedermann, Christoph, Jack, Robert L., Grey, Clare P., Rao, Akshay

Issue&Volume: 2026-07-29

Abstract: Although graphite is the most widely used negative electrode material in lithium-ion batteries1, its lithium insertion processes and associated dynamics, particularly those of the dilute stages, remain poorly understood. A fundamental understanding of how symmetry-breaking phase transitions occur continuously under operating conditions is lacking. Here, using operando optical microscopy, we provide a unified picture of ion intercalation dynamics during the dilute stages of graphite intercalation, showing that the graphitic particles undergo rapid, localized deintercalation–intercalation step events, leading to deintercalation–intercalation of micrometre-sized regions within seconds. These are reminiscent of a phase-transition phenomenon, ‘avalanches’, which occurs in disordered materials, involving step changes in the order parameter due to jumps between multiple metastable states2,3. Using a modified random field Ising model, the avalanches are related to static disorder, which disrupts intercalation dynamics. The model can also account for the apparently continuous transitions between stages and the experimental avalanche statistics. Finally, we develop a methodology to spatio-temporally analyse the sequences of avalanche events, revealing considerable heterogeneous connectivity. Our work highlights the role of local and static disorder in explaining unexpected phase-transition behaviour and provides new tools and concepts for studying layered battery materials.

DOI: 10.1038/s41586-026-10862-4

Source: https://www.nature.com/articles/s41586-026-10862-4