富锂层状氧化物正极材料研究进展

doi:10.15541/jim20160563

摘要/Abstract

摘要：

富锂层状氧化物正极材料(xLi₂MnO₃·(1-x)LiMO₂(M=Ni_yMn_zCo_1-y-z….)理论容量高、价格低廉, 是新一代锂离子电池正极材料的候选之一。本文概述了该正极材料的结构, 分析了其在电化学活化过程与循环过程中结构的演变, 探讨了结构变化对正极材料电化学性能的影响规律, 并概括了目前针对该类正极材料电化学性能提升所开展的离子掺杂和表面改性的研究工作, 展望了未来富锂层状氧化物正极材料的发展方向。

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关键词: 富锂层状氧化物, 活化和循环过程, 晶相结构演变, 表面改性, 离子掺杂, 综述

Abstract:

Lithium rich layered oxide cathode materials (xLi₂MnO₃·(1-x)LiMO₂(M=Ni_yMn_zCo_1-y-z….) are one of the candidate cathode materials for the new generation of lithium ion batteries because of the high theoretical capacity and low cost. In this paper, the structure of the cathode materials and the structure activation and evolution within initial charge-discharge and the cycling process were outlined, the effect of structure evolution on electrochemical evolution of the Li-rich cathode materials were further investigated. And, the current works of ion doping and surface modification on the cathode materials to enhance electrochemical properties were summarized and the development trend of different lithium rich layered oxide cathode materials was described.

Key words: lithium rich layered oxide, activated and cycled process, structure transform, surface modification, cation doping, review

中图分类号:

TM911

陈宇方, 李宇杰, 郑春满, 谢凯, 陈重学. 富锂层状氧化物正极材料研究进展[J]. 无机材料学报, 2017, 32(8): 792-800.

CHEN Yu-Fang, LI Yu-Jie, ZHENG Chun-Man, XIE Kai, CHEN Zhong-Xue. Research Development on Lithium Rich Layered Oxide Cathode Materials[J]. Journal of Inorganic Materials, 2017, 32(8): 792-800.

图/表 4

图1 层状六方晶相与单斜晶相的过渡金属离子和锂离子占位示意图((a)层状六方晶相; (b)单斜晶相)[7, 9]

Fig. 1 Scheme of crystal structure and cation occupancy of transition metal cation and lithium ions in layered rohomohedral phase and monoclinic structure (a) Layered rohomohedral phase; (b) Monoclinic phase[7, 9]

图2 Li2MnO3晶体结构的堆积位错示意图和不同位错对应的XRD图谱((a)离子堆积方式; (b)不同位错的XRD拟合图谱)[2, 11]

Fig. 2 Scheme of stacking fault and XRD patterns for various stacking fault in Li2MnO3 (a) Ionics stacking; (b) XRD simulation pattern of Li2MnO3 with various stacking fault)[2, 11]

图3 富锂固溶体层状晶相向尖晶石相转变的可能机理[42]

Fig. 3 Proposed layered-to-spinel transformation mechanism for lithium layered cathode materials[42]

表1 富锂层状氧化物正极材料表面包覆改性研究

Table 1 Studies on coating the lithium-rich cathode materials

	Surface modified materials	Initial culombical efficiency (%)	Capacity rentention(%)
Unelectrochemical activity oxides	Al₂O₃^{[68, 69]}, ZrO₂^{[69, 70]}, ZnO^[69], Ta₂O₅^[69], Nb₂O₅^[69]	[87.4, (77.1)]^[68] [98, 96, 97, 96, 98(92)]^[69],	[90, 84, 89, 84, 87(60)]^[69] 94.9(87.5)^[70]
Electrochemical activity oxides	V₂O₅^[71], MnO₂^[72], FePO₄^[73]	85(79)^[71], 90(83)^[72], 85.1-100(79)^[73]	90(50)^[71] 93(89)^[72] 95(84.9)^[73]
Fluorides	AlF₃^[74]	90.8(82.8)^[74]	91.6(73.4)^[74]
C Derivative	C ^{[75, 76]}	96.7(84)^[75] 79.5(74)^[76]	92(44)^[75] 85.1(74.7)^[76]
Other materials	AlPO₄^{[68, 77]} Li₂SiO₃^[77]	92.2(77.1)^[68] 78.9(66.5)^[77] 76.4(69.6)^[77]	73(65)^[77], 92(71)^[77]

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