Nanoscale Surface Modification of Lithium-Rich Layered-Oxide Composite Cathodes for Suppressing Voltage Fade

Fenghua Zheng; Chenghao Yang; Xunhui Xiong; Jiawen Xiong; Renzong Hu; Yu Chen; Meilin Liu

doi:10.1002/anie.201506408

Nanoscale Surface Modification of Lithium-Rich Layered-Oxide Composite Cathodes for Suppressing Voltage Fade

Angew Chem Int Ed Engl. 2015 Oct 26;54(44):13058-62. doi: 10.1002/anie.201506408. Epub 2015 Sep 3.

Authors

Fenghua Zheng¹, Chenghao Yang², Xunhui Xiong¹, Jiawen Xiong¹, Renzong Hu³, Yu Chen⁴, Meilin Liu^{5

6}

Affiliations

¹ New Energy Research Institute, College of Environment and Energy, South China University of Technology, 382 Waihuan Road, Guangzhou Higher Education Mega Center, Guangzhou 510006 (P. R. China).
² New Energy Research Institute, College of Environment and Energy, South China University of Technology, 382 Waihuan Road, Guangzhou Higher Education Mega Center, Guangzhou 510006 (P. R. China). esyangc@scut.edu.cn.
³ School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (P. R. China).
⁴ School of Materials Science & Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (USA).
⁵ New Energy Research Institute, College of Environment and Energy, South China University of Technology, 382 Waihuan Road, Guangzhou Higher Education Mega Center, Guangzhou 510006 (P. R. China). meilin.liu@mse.gatech.edu.
⁶ School of Materials Science & Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (USA). meilin.liu@mse.gatech.edu.

PMID: 26335589
DOI: 10.1002/anie.201506408

Abstract

Lithium-rich layered oxides are promising cathode materials for lithium-ion batteries and exhibit a high reversible capacity exceeding 250 mAh g(-1) . However, voltage fade is the major problem that needs to be overcome before they can find practical applications. Here, Li1.2 Mn0.54 Ni0.13 Co0.13 O2 (LLMO) oxides are subjected to nanoscale LiFePO4 (LFP) surface modification. The resulting materials combine the advantages of both bulk doping and surface coating as the LLMO crystal structure is stabilized through cationic doping, and the LLMO cathode materials are protected from corrosion induced by organic electrolytes. An LLMO cathode modified with 5 wt % LFP (LLMO-LFP5) demonstrated suppressed voltage fade and a discharge capacity of 282.8 mAh g(-1) at 0.1 C with a capacity retention of 98.1 % after 120 cycles. Moreover, the nanoscale LFP layers incorporated into the LLMO surfaces can effectively maintain the lithium-ion and charge transport channels, and the LLMO-LFP5 cathode demonstrated an excellent rate capacity.

Keywords: doping; electrochemistry; lithium oxides; lithium-ion batteries; surface coatings.