Enhanced Electrochemical Performance of Li1.27Cr0.2Mn0.53O₂ Layered Cathode Materials via a Nanomilling-Assisted Solid-state Process

Chengkang Chang; Jian Dong; Li Guan; Dongyun Zhang

doi:10.3390/ma12030468

Enhanced Electrochemical Performance of Li_1.27Cr_0.2Mn_0.53O₂ Layered Cathode Materials via a Nanomilling-Assisted Solid-state Process

Materials (Basel). 2019 Feb 3;12(3):468. doi: 10.3390/ma12030468.

Authors

Chengkang Chang^{1

2}, Jian Dong³, Li Guan⁴, Dongyun Zhang⁵

Affiliations

¹ School of Materials Science and Engineering, Shanghai Institute of Technology,100 Haiquan Road, Shanghai 201418, China. ckchang@sit.edu.cn.
² Shanghai Innovation Institute for Materials, Shanghai University, Shanghai 200444, China. ckchang@sit.edu.cn.
³ School of Materials Science and Engineering, Shanghai Institute of Technology,100 Haiquan Road, Shanghai 201418, China. theanswer0328@gmail.com.
⁴ School of Materials Science and Engineering, Shanghai Institute of Technology,100 Haiquan Road, Shanghai 201418, China. lguan@sit.edu.cn.
⁵ School of Materials Science and Engineering, Shanghai Institute of Technology,100 Haiquan Road, Shanghai 201418, China. dyz@sit.edu.cn.

Abstract

Li_1.27Cr_0.2Mn_0.53O₂ layered cathodic materials were prepared by a nanomilling-assisted solid-state process. Whole-pattern refinement of X-ray diffraction (XRD) data revealed that the samples are solid solutions with layered α-NaFeO₂ structure. SEM observation of the prepared powder displayed a mesoporous nature composed of tiny primary particles in nanoscale. X-ray photoelectron spectroscopy (XPS) studies on the cycled electrodes confirmed that triple-electron-process of the Cr³⁺/Cr⁶⁺ redox pair, not the two-electron-process of Mn redox pair, dominants the electrochemical process within the cathode material. Capacity test for the sample revealed an initial discharge capacity of 195.2 mAh·g^-1 at 0.1 C, with capacity retention of 95.1% after 100 cycles. EIS investigation suggested that the high Li ion diffusion coefficient (3.89 × 10^-10·cm²·s^-1), caused by the mesoporous nature of the cathode powder, could be regarded as the important factor for the excellent performance of the Li_1.27Cr_0.2Mn_0.53O₂ layered material. The results demonstrated that the cathode material prepared by our approach is a good candidate for lithium-ion batteries.

Keywords: Cr3+/Cr6+ redox pairs; X-ray diffraction; cathode material; cycling performance; specific capacity.