Ternary Cathode Materials Prepared By Induction Sintering Incorporated with Carbon Coating Technique for High Performance Li-Ion Batteries

Abstract

Lithium-ion battery has become the front-runner among rechargeable-battery technologies, having found applications in industries as diverse as portable electronics and electric vehicles (EVs) [1,2]. Recently, a number of attempts have been made to partially substitute Ni with other elements such as Co and Al doping. Among the resulting cathodes, LiNi0.8Co0.15Al0.05O2 (LNCA) is considered as one of the promising alternatives to replace LiCoO2 owing to its higher specific capacity and better environmental friendliness [3,4]. Generally, solid-state calcination was carried out under oxygen-containing atmosphere at 700–900°C for 15 hr. To shorten the growth period, this work proposes an efficient method of preparing LNCA cathode material by using induction sintering incorporated with carbon coating technique. The electrochemical performance of C-coated LNCA cathodes was well characterized by cyclic voltammetry (CV) and charge-discharge cycling. This study aims at examining the possibility of induction sintering route for preparing C-coated LNCA cathode materials for high-performance Li-ion batteries in practical or industrial applications. We have successfully investigated the electrochemical performance of LNCA cathodes, using CV and charge-discharge cycling at 0.1−5C. An efficient induction route was adopted to synthesize LNCA powders at 700°C within a shorter calcination period (3 h), as compared with traditional heating methods. The as-prepared layered C-coated LNCA crystals possessed a low degree of cation mixing with highly hexagonal ordering. For 0.1C charge-discharge cycling, the discharge capacity of LNCA cathode could attain as high as 201 mAh g-1, and there was an increased capacity of 10.3% as compared with the fresh one. On the basis of the experimental results, the C-coated LNCA cathode remained higher capacity retention of 88.1% after 50 cycles at 1C. Accordingly, the induction route offered a promising pathway to commercially synthesize high-crystalline LNCA cathode materials for high-performance Li-ion batteries, favoring the application of EVs in the near future.