阴离子密堆二次电池正极材料中离子宿住迁移与能量存蓄机制晶体化学新探索  

New exploration based on crystal chemistry of ion migration and energy storage mechanism in anion-close-packed cathode materials for rechargeable battery

作　　者：梁叔全[1,2] 郭珊 何伟[3] 曹鑫鑫[1,2] 马君剑 周江[1,2] 方国赵 LIANG Shuquan;GUO Shan;HE Wei;CAO Xinxin;MA Junjian;ZHOU Jiang;FANG Guozhao(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Key Laboratory of Electronic Packaging and Advanced Functional Materials of Hunan Province,Central South University,Changsha 410083,China;School of Mathematics and Statistics,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学电子封装及先进功能材料湖南省重点实验室,长沙410083 [3]中南大学数学与统计学院,长沙410083

出　　处：《中国有色金属学报》2024年第6期1769-1785,共17页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51932011,52272260)。

摘　　要：在二次电池电极材料中,有一类性能优良的材料具有阴离子密堆或近密堆方式构筑的晶体结构。宿住阳离子在密堆留下的空隙空间中宿住、迁移,从而实现能量转换与存储。相关过程微观机理的研究由于涉及原子尺度的微观结构辨析和电子层面的分析,实验研究难度较大。因此,更多是通过晶体学理论分析与晶体场理论和量子力学第一性原理计算结合展开。已有的理论从过渡金属配位体晶体场分析展开,但宿住离子宿住迁移中电子相互作用关注相对不足。本文根据已有的实验事实,在精准描述最具代表性的阴离子(氧离子)面心立方紧密堆积(FCC)结构中空隙空间准确形态和微分几何方法准确解析空腔真实体积的基础上,结合空隙空腔独特形态,对经典晶体学中Pauling第一规则的分析方法作了拓展。根据新的理解,提出了宿住阳离子在空隙空腔宿住和徒迁拓扑形变新模式,及其可能拥有的电子形态学新特征,提出了空隙空腔中宿住阳离子体积与密堆阴离子半径间的新关系。为了进一步说明住宿离子电子形态特征,通过第一性原理计算获得了典型FCC结构LiMn_(2)O_(4)尖晶石中电子密度等势图,构造了锂离子宿住四面体空隙空腔的电子密度等势特征分布的三维形态,与晶体学分析中获得的电子形态新特征变化一致。通过夹在两个密排面间的{110}面族电子云密度分布分析,首次清晰地揭示了LiMn_(2)O_(4)中锂离子的“S”形徒迁途径,及其对附近锰离子配位多面体电子云密度分布的影响。依据宿住离子脱/嵌新特征,提出阴离子拓扑多面体晶体场对宿住阳离子电子云压缩发生拓扑变形实现能量转换储蓄的新思路,据此计算了典型紧密堆积构造的电极材料新的理论能量密度,并和传统方法计算的理论值进行了比较,二者十分接近,为从晶体学和量子力学理解二次电池能量储存提供了Among the electrode materials of secondary batteries,there exists a class of high-performance electrode materials with anionic close or near-close packed structures.The host cations reside and migrate within the interstitial spaces left by the close stack,thus realizing the conversion between electrical energy and chemical energy.Experimental study on the microscopic mechanism of related processes is difficult because it involves the analysis of atomic scale microstructure.Therefore,it is mainly carried out through the combination of crystallographic theoretical analysis,crystal field theory and first principles of quantum mechanics.Existing theories have been developed from the crystal field analysis of transition metal ligands,but relatively little attention has been paid to the electron interaction in the host ion migration.In this study,according to the previous research findings,Pauling's first rule in classical crystallography was extended on the basis of the accurate description of the interstitial space of oxygen ion(the most representative anion) face-centered cubic close packed(FCC) structure,and the accurate analysis of the interstitial volume by differential geometry analytical calculation.Based on the new understanding,we proposed a new topological deformation model that host cations reside and migrate within interstitial sites,as well as developing a novel electron morphology,and a new relationship between the volume of host cations and the radius of packed anions.To further elucidate the electron morphology characteristics of the host ion,we obtained the electron density equipotential map in LiMn_(2)O_(4) spinel with a typical FCC structure through first principles calculations.The three-dimensional shape of the electron density equipotential distribution in the tetrahedral interstitial space for the host Li ion was also constructed,which was consistent with the new electron morphological characteristics obtained in the crystallographic analysis.Through the analysis of the electron cloud density di

关 键 词：二次电池 密堆积正极材料 离子迁移 能量存蓄机制 晶体化学分析 第一性原理计算 

分 类 号：O646[理学—物理化学]