Synthesis Routes on Electrochemical Behavior of Co-Free Layered LiNi0.5Mn0.5O2 Cathode for Li-Ion Batteries

Shu-Yi Tsai; Kuan-Zong Fung

doi:10.3390/molecules28020794

Synthesis Routes on Electrochemical Behavior of Co-Free Layered LiNi_0.5Mn_0.5O₂ Cathode for Li-Ion Batteries

Molecules. 2023 Jan 13;28(2):794. doi: 10.3390/molecules28020794.

Authors

Shu-Yi Tsai¹, Kuan-Zong Fung²

Affiliations

¹ Hierarchical Green-Energy Materials (Hi-GEM) Research Center, No. 1, Ta-Hsueh Road, Tainan 70101, Taiwan.
² Department of Materials Science and Engineering, National Cheng Kung University, No. 1, Ta-Hsueh Road, Tainan 70101, Taiwan.

Abstract

Co-free layered LiNi_0.5Mn_0.5O₂ has received considerable attention due to high theoretical capacity (280 mAh g^-1) and low cost comparable than LiCoO₂. The ability of nickel to be oxidized (Ni²⁺/Ni³⁺/Ni⁴⁺) acts as electrochemical active and has a low activation energy barrier, while the stability of Mn⁴⁺ provides a stable host structure. However, selection of appropriate preparation method and condition are critical to providing an ideal layered structure of LiNi_0.5Mn_0.5O₂ with good electrochemical performance. In this study, Layered LiNi_0.5Mn_0.5O₂ has been synthesized by sol-gel and solid-state routes. According to the XRD, the sol-gel method provides a pure phase, and solid-state process only minimize the secondary phases to certain limit. The Ni²⁺/Mn⁴⁺ content in the sol-gel process was higher than in the solid-state reaction, which may be due to the chemical composition homogeneity of the sol-gel samples. Regarding the electrochemical behavior, sol-gel process is better than solid-state reaction. The discharge capacity is 145 mAh/g and 91 mAh/g for the sol-gel process and solid-state reaction samples, respectively.

Keywords: Co-free; LiNi0.5Mn0.5O2; layer structure.

Grants and funding

This work was financially supported by National Science and Technology Council of Taiwan for the project No., NSTC 111-2635-E-006-004, 111-2221-E-006-096-MY2.