(1. 昆明理工大学 冶金与能源工程学院，昆明 650093；
2. 昆明理工大学 锂离子电池与材料制备技术国家地方联合工程实验室，昆明 650093；
3. 云南驰宏国际锗业有限公司，曲靖 655011)
摘 要: 过渡金属草酸盐基于其高比容量、优异的倍率性能、简单的制备工艺和丰富的资源等优势，在高能量锂离子电池储能领域拥有巨大的应用潜力。然而由于其较低的电子电导率和Li+迁移速率，在循环过程中会形成大量电化学反应活性较低的金属纳米粒子和聚合物，引起更高的不可逆容量，并且不稳定的层状结构会造成颗粒的破裂，导致电池的循环寿命较差。此外，过渡金属草酸盐特殊的热力学特性，导致获得100%失结晶水材料更加困难。本文综述了过渡金属草酸盐材料的晶体结构特征，基于对储锂过程中材料转换过程的理解和界面特性等机理研究并结合材料面临的主要挑战，深入分析了近年来在形貌微纳结构调控和增强产物反应活性等方面的改性策略及其作用机理，为推动高能量密度过渡金属草酸盐基负极材料在锂离子电池方面的基础科学研究和商业化应用提供借鉴参考。
关键字: 过渡金属草酸盐；储能机制；转换反应；微纳结构调控；锂离子电池；研究进展
（1. Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China;
2. National Local Joint Engineering Laboratory of Lithium Ion Battery and Material Preparation Technology, Kunming University of Science and Technology, Kunming 650093, China;
3. Yunnan Chihong International Germanium Industry Co., Ltd., Qujing 655011, China）
Abstract:Transition metal oxalates (TMOxs) exhibit great application potential as anode materials for high-energy density in lithium ion batteries, because of their higher electrochemical capacity, more excellent rate performance, and environmental friendliness. However, the lower electronic conductivity and slower migration of Li+ cause the formation of plenty of electrochemical production (metal nanoparticles and oxalate matrix) with reaction activity during the initial cycles, which creates larger irreversible capacity. In addition, a certain degree of disorder for their three-dimensional (3D) multi-layered structure can result in the collapse and crack around the edge of layer in micro- or nano-particles and shorten the cycling life of electrode materials. Furthermore, because of the similar temperatures for decomposition and losing crystalline water, the complete utilization of TMOxs is also challenged by the difficulty to obtain 100% free water material through dehydration. This paper detailedly reviews various crystal structures of TMOxs. Based on the understanding of confronting challenges and energy storage mechanism for TMOxs, such as the conversion reaction and interface characteristics during cycling, the modified strategies, especially in controlling of morphologies and micro-nano structure and elevating the electrochemical reactive activation for outcoming, are deeply analyzed. This paper also provides wide reference for promoting the fundamental researching and commercial application of high-energy TMOxs as anode materials in lithium-ion batteries.
Key words: transition metal oxalate; energy storage mechanism; conversion reaction; micro-nano structure regulation; lithium ion batteries; research progress
