Preparation and electrochemical performance of carbon-coated LiFePO4/LiMnPO4-positive material for a Li-ion battery--颗粒学报PARTICUOLOGY

Tan, Q., Yan, B., Xu, Y., Chen, Y., & Yang, J. (2017). Preparation and electrochemical performance of carbon-coated LiFePO4/LiMnPO4-positive material for a Li-ion battery. Particuology, 30, 144-150. https://doi.org/10.1016/j.partic.2016.05.008

Preparation and electrochemical performance of carbon-coated LiFePO₄/LiMnPO₄-positive material for a Li-ion battery

Qiangqiang Tan^a, Bo Yan ^{a b}, Yuxing Xu ^a, Yunfa Chen ^a, Jun Yang ^a *

a State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
b University of Chinese Academy of Sciences, Beijing 100049, China

10.1016/j.partic.2016.05.008

Volume 30, February 2017, Pages 144-150

Received 13 April 2016, Revised 6 May 2016, Accepted 21 May 2016, Available online 14 September 2016, Version of Record 27 January 2017.

E-mail: jyang@ipe.ac.cn

Highlights

• LiMn_0.7Fe₀_.3PO₄–LiFePO₄–C was fabricated by ball milling and high-temperature sintering.

• The synthesized core–shell structure had a concentration gradient of Fe and Mn.

• Core–shell LiFePO₄/LiMnPO₄ as positive material showed high discharge capacity.

• Core–shell structure had high electrical conductivity and Li-ion transport rate.

Abstract

Lithium iron phosphate (LiFePO₄)/lithium manganese phosphate (LiMnPO₄)-positive material was successfully prepared through ball milling and high-temperature sintering using manganese acetate, lithium hydroxide, ammonium dihydrogen phosphate, and ferrous oxalate as raw materials. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, a constant current charge–discharge test, cyclic voltammetry, and electrochemical impedance spectroscopy. The effects of lithium iron phosphate coating were also discussed. Because of its special core–shell structure, the as-prepared LiMn_0.7Fe_0.3PO₄–LiFePO₄–C exhibits excellent electrochemical performance. The discharge capacity reached 136.6 mAh/g and the specific discharge energy reached 506.9 Wh/kg at a rate of 0.1 C.

Graphical abstract

Keywords

LiMn_1−xFe_xPO₄; Composite; Core–shell structure; Positive material; Li-ion battery

文章导读