Pei Zhengqing, Wang Jiawei, Wang Haifeng, Zheng Kexin, Wang Qian, Zhou Xinjie, Ma Dehua, Lu Ju
School of Materials and Metallurgy, Guizhou University, Guiyang 550025, China.
Guizhou Provincial Key Laboratory of Metallurgical Engineering and Energy Saving, Guiyang 550025, China.
Int J Mol Sci. 2024 Dec 10;25(24):13270. doi: 10.3390/ijms252413270.
LiMnO, a significant cathode material for lithium-ion batteries, has garnered considerable attention due to its low cost and environmental friendliness. However, its widespread application is constrained by its rapid capacity degradation and short cycle life at elevated temperatures. To enhance the electrochemical performance of LiMnO, we employed a liquid-phase co-precipitation and calcination method to incorporate Cr into the LiMnO cathode material, successfully synthesizing a series of LiCrMnO (x = 0~0.06). The prepared Cr-doped samples exhibited an excellent spinel structure and a unique truncated octahedral morphology. Additionally, the substitution of Mn in LiMnO by Cr, coupled with the significantly higher Cr-O bond energy compared to Mn-O bond energy, enhanced the stability of the crystal structure and inhibited the Jahn-Teller effect. Experimental results demonstrated that the optimized LiCrMnO displayed superior electrochemical performance, with a capacity retention rate of 93.24% after 500 cycles under a 0.5C current density; even at 50 °C, the capacity retention rate remained at 86.46% after 350 cycles under a 0.5C current density. The polyhedral morphology formed by Cr doping in LiMnO offers an effective approach to achieving high-performance LiMnO cathode materials.
LiMnO是一种重要的锂离子电池正极材料，因其低成本和环境友好性而备受关注。然而，其广泛应用受到高温下容量快速衰减和循环寿命短的限制。为了提高LiMnO的电化学性能，我们采用液相共沉淀和煅烧方法将Cr掺入LiMnO正极材料中，成功合成了一系列LiCrMnO（x = 0~0.06）。制备的Cr掺杂样品表现出优异的尖晶石结构和独特的截角八面体形态。此外，Cr取代LiMnO中的Mn，以及Cr-O键能比Mn-O键能显著更高，增强了晶体结构的稳定性并抑制了 Jahn-Teller 效应。实验结果表明，优化后的LiCrMnO表现出优异的电化学性能，在0.5C电流密度下500次循环后容量保持率为93.24%；即使在50°C下，在0.5C电流密度下350次循环后容量保持率仍为86.46%。LiMnO中Cr掺杂形成的多面体形态为实现高性能LiMnO正极材料提供了一种有效方法。
