Journal of Energy Chemistry ( IF 14.0 ) Pub Date : 2020-04-14 , DOI: 10.1016/j.jechem.2020.03.042
Renheng Wang , Yiling Sun , Kaishuai Yang , Junchao Zheng , Yan Li , Zhengfang Qian , Zhenjiang He , Shengkui Zhong
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To solve the critical problems of lithium rich cathode materials, e.g., structure instability and short cycle life, we have successfully prepared a ZrO2-coated and Zr-doping xLi2MnO3∙(1–x)LiMO2 hollow architecture via one-time sintering process. The modified structural materials as lithium-ion cathodes present good structural stability and superior cycle performance in LIBs. The discharge capacity of the ZrO2-coated and Zr-doped hollow pristine is 220 mAh g−1 at the 20th cycle at 0.2 C (discharge capacity loss, 2.7%) and 150 mAh g−1 at the 100th cycle at 1 C (discharge capacity loss, 17.7%), respectively. However, hollow pristine electrode only delivers 203 mAh g−1 at the 20th cycle at 0.2 C and 124 mAh g−1 at the 100th cycle at 1 C, respectively, and the corresponding to capacity retention is 92.2% and 72.8%, respectively. Diffusion coefficients of modified hollow pristine electrode are much higher than that of hollow pristine electrode after 100 cycles (approach to 1.4 times). In addition, we simulate the adsorption reaction of HF on the surface of ZrO2-coated layer by the first-principles theory. The calculations prove that the adsorption energy of HF on the surface of ZrO2-coated layer is about -1.699 eV, and the ZrO2-coated layer could protect the hollow spherical xLi2MnO3∙(1–x)LiMO2 from erosion by HF. Our results would be applicable for systematic amelioration of high-performance lithium rich material for anode with the respect of practical application.
中文翻译:
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一次烧结法修饰x Li 2 MnO 3(1 -x)LiMO 2空心结构并研究其增强的电化学性能
为解决富锂正极材料的关键问题,例如结构不稳定性和循环寿命短,我们通过一种方法成功制备了ZrO 2涂层和Zr掺杂x Li 2 MnO 3 ∙(1– x)LiMO 2空心结构烧结过程。作为锂离子阴极的改性结构材料在LIB中具有良好的结构稳定性和出色的循环性能。涂覆有ZrO 2和掺杂ZrO 2的中空原始金属在第20个循环中在0.2 C下的放电容量为220 mAh g -1(放电容量损失2.7%),在150 mAh g -1下在第1循环的第100个循环中(放电容量损失为17.7%)。然而,中空原始电极仅输送203毫安克-1在以0.2C和124毫安克第20次循环-1以1℃,在第100次循环分别与对应于容量保持为分别为92.2%和72.8%。经过100次循环(接近1.4倍)后,改性空心空心电极的扩散系数大大高于空心空心电极的扩散系数。此外,我们用第一性原理模拟了HF在ZrO 2涂层表面的吸附反应。计算证明,HF在ZrO 2涂层表面的吸附能约为-1.699 eV,而ZrO 2涂层可以保护空心球形x Li 2 MnO 3 ∙(1- x)LiMO 2免受HF腐蚀。考虑到实际应用,我们的结果将可用于系统改善阳极用高性能富锂材料。