Improvement of electrochemical properties of LiFe0.9Zn0.1-xMnxPO4 (x=0, 0.05, 0.075, 0.1) by double doping with Zn2+, Mn2

• Published in: Journal of solid state chemistry 2024-12, Vol.340, p.125015, Article 125015
• Main Authors: Li, Bowen, Pan, Chengyu, Chen, Jiamin, Yin, Haoyan, He, Jiaqi, Xie, Weicheng, Gao, Yanmin
• Format: Article
• Language: English
• Subjects: Electrochemical performance; Hydrothermal method; Li-ion battery; LiFePo4; Mn2+ doping; Zn2+ doping
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2024.125015

Zn2+ and Mn2+ co-doped LiFe0.9Zn0.1-xMnxPO4 (where x = 0, 0.05, 0.075, 0.1) composites are synthesized by a simple one-step hydrothermal method. The composition, structure, morphology and electrochemical properties of the materials are fully characterized using XRD, SEM, TEM, EDS, CV and AC impedance tests. The results show that the co-doping of Zn2+ and Mn2+ preserves the olivine structure of LiFePO4 and also stabilizes the crystal structure, reduces the charge transfer resistance and improves the Li+ diffusion rate. When the initial specific capacity of the cathode material with the doping ratio of Zn = 0.025 and Mn = 0.075 is 161.8 mAh·g−1, the discharge specific capacity after 200 cycles is still as high as 157.8 mAh·g−1 with a capacity retention of 97.5 %, which is obviously better than the rest of the materials. [Display omitted] •The selected method is simple and the experiment is highly reproducible.•Selection of zinc and manganese salts with excellent water solubility.•Mn2+ can support the crystal structure and increase the crystal plane spacing.•Zn2+ improves the cyclic stability of the material.