Improving the rate performance of LiNi 0.5 Mn 0.5 O 2 material at high voltages by Cu-doping
- PDF / 1,288,349 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 5 Downloads / 171 Views
ORIGINAL PAPER
Improving the rate performance of LiNi0.5Mn0.5O2 material at high voltages by Cu-doping Guofeng Jia 1,3,4 & Xuehui Shangguan 2 & Suqin Liu 1,4 & Zhen He 1,4 Received: 10 May 2020 / Revised: 18 June 2020 / Accepted: 29 June 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract A series of LiNi0.5-xCuxMn0.5O2 (0 ≤ x ≤ 0.05) samples were synthesized through a combination of co-precipitation (CP) and solid-state reaction. The synthesized cathode materials were systematically investigated by X-ray diffraction (XRD), Rietveld refinement, inductively coupled plasma (ICP) spectroscopy, X-ray photoelectron spectroscopy (XPS), and charge-discharge tests. The structural measurements indicated that Cu2+ was successfully doped into the structure of the LiNi0.5Mn0.5O2 material. The results of the electrochemical measurements suggest that the electrochemical performances of LiNi0.5Mn0.5O2 can be obviously improved by Cu -doping, and the best doping amount is 1 mol%. Specifically, the capacity retention of a 1 mol% Cu-doped sample is 18% higher than that of pure LiNi0.5Mn0.5O2 in the range of 2.5~4.6 V at 0.2 C. Most importantly, the cycle stability of LiNi0.5Mn0.5O2 at high currents can also be improved by Cu-doping. We found that Cu-doping can lower the Li/Ni cation mixing, enlarge the migration channels of lithium ions, reduce migration resistance, and retard polarization, and in turn, it can improve the electrochemical properties of LiNi0.5Mn0.5O2. Keywords Lithium-ion batteries . Cathode LiNi0.5Mn0.5O2 . Cu-doping . Li/Ni cation mixing
Introduction To meet the need of energy storage, more and more scientists have paid great attention to rechargeable lithium-ion batteries (LIBS). This is due to their excellent electrochemical performances, such as long lifetimes, and high energy and power densities [1–3]. The cathode material, which is the most important part of lithium-ion batteries, plays a critical role in determining the electrochemical properties [4, 5]. LiCoO2 has been the main cathode material used in commercial
lithium-ion batteries since 1992 [6–8]. However, it has some inherent shortcomings in terms of cost, poor Li+ diffusion coefficient, and poor charge-discharge capacity, which prevent its extensive application [9–11]. Hence, many other cathode materials have been studied to meet the needs of society [12–15]. LiNi0.5Mn0.5O2 cathode material, with the same layered αNaFeO2 structure as that of LiCoO2, is particularly attractive. This is because of its merits, e.g., low cost, high specific capacity and safety [16–18]. In the structure of this material,
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11581-020-03683-6) contains supplementary material, which is available to authorized users. * Xuehui Shangguan [email protected]
3
Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Key Laboratory of Salt Lake Resources Chemistry of Qinghai province, Qinghai Institute of Salt Lakes, Chinese
Data Loading...
