Lithium-excess olivine electrode for lithium rechargeable batteries

被引：62

作者：

Park, Kyu-Young ^{[1
,2
,3
,4
]}

Park, Inchul ^{[1
,2
,3
,4
]}

Kim, Hyungsub ^{[1
,2
,3
,4
,5
]}

Yoon, Gabin ^{[1
,2
]}

Gwon, Hyeokjo ^{[6
]}

Cho, Yongbeom ^{[1
,2
]}

Yun, Young Soo ^{[7
]}

Kim, Jung-Joon ^{[1
,2
]}

Lee, Seongsu ^{[5
]}

Ahn, Docheon ^{[8
]}

Kim, Yunok ^{[9
]}

Kim, Haegyeom ^{[1
,2
]}

Hwang, Insang ^{[1
,2
]}

Yoon, Won-Sub ^{[9
]}

Kang, Kisuk ^{[1
,2
,3
,4
]}

机构：

[1] Seoul Natl Univ, Dept Materials Sci & Engn, 1 Gwanak Ro, Seoul 151742, South Korea

[2] Seoul Natl Univ, RIAM, 1 Gwanak Ro, Seoul 151742, South Korea

[3] Seoul Natl Univ, Ctr Nanoparticle Res, 1 Gwanak Ro, Seoul, South Korea

[4] Seoul Natl Univ, Inst Basic Sci, 1 Gwanak Ro, Seoul, South Korea

[5] Korea Atom Energy Res Inst, 989 Beon Gil, Daejeon, South Korea

[6] Samsung Elect Co Ltd, Mat Res Ctr, Samsung Adv Inst Technol, Energy Lab, 130 Samsung Ro, Suwon 16678, Gyeonggi Do, South Korea

[7] Kangwon Natl Univ, Dept Chem Engn, Samcheok 245711, South Korea

[8] Pohang Accelerator Lab, Beamline Dept, 80 Jigokro,127-Beongil, Pohang, Kyungbuk, South Korea

[9] Sungkyunkwan Univ, Dept Energy Sci, Suwon 151742, South Korea

来源：

ENERGY & ENVIRONMENTAL SCIENCE | 2016年 / 9卷 / 09期

基金：

新加坡国家研究基金会;

关键词：

LI-ION BATTERIES; LAYERED-OXIDE ELECTRODES; CATHODE MATERIALS; HYDROTHERMAL SYNTHESIS; ELECTROCHEMICAL PROPERTIES; MAS NMR; LIFEPO4; NANOPARTICLES; UNSUPPORTED CLAIMS; ANTISITE DEFECTS; IRON PHOSPHATE;

D O I：

10.1039/c6ee01266c

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Lithium iron phosphate (LFP) has attracted tremendous attention as an electrode material for next-generation lithium-rechargeable battery systems due to the use of low-cost iron and its electrochemical stability. While the lithium diffusion in LFP, the essential property in battery operation, is relatively fast due to the one-dimensional tunnel present in the olivine crystal, the tunnel is inherently vulnerable to the presence of Fe-Li anti-site defects (Fe ions in Li ion sites), if any, that block the lithium diffusion and lead to inferior performance. Herein, we demonstrate that the kinetic issue arising from the Fe-Li defects in LFP can be completely eliminated in lithium-excess olivine LFP. The presence of an excess amount of lithium in the Fe ion sites (Li-Fe) energetically destabilizes the Fe-Li-related defects, resulting in reducing the amount of Fe defects in the tunnel. Moreover, we observe that the spinodal decomposition barrier is notably reduced in lithium-excess olivine LFP. The presence of Li-Fe and the absence of Fe-Li in lithium-excess olivine LFP additionally induce faster kinetics, resulting in an enhanced rate capability and a significantly reduced memory effect. The lithium-excess concept in the electrode crystal brings up unexpected properties for the pristine crystal and offers a novel and interesting approach to enhance the diffusivity and open up additional diffusion paths in solid-state ionic conductors.

引用

页码：2902 / 2915

页数：14

共 74 条

[1] Singular Structural and Electrochemical Properties in Highly Defective LiFePO4 Powders [J].