Enhancing the Electrochemical Performance of a High-Voltage LiNi(0.5)Mn(1.5)O(4)Cathode in a Carbonate-Based Electrolyte with a Novel and Low-Cost Functional Additive
Enhancing the Electrochemical Performance of a High-Voltage LiNi(0.5)Mn(1.5)O(4)Cathode in a Carbonate-Based Electrolyte with a Novel and Low-Cost Functional Additive
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使用新型低成本功能添加剂提高碳酸盐基电解质中高压 LiNi0.5Mn1.5O4 正极的电化学性能
DOI：
10.1002/chem.202001870
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发表时间：
2020
影响因子：
4.3
通讯作者：
Li Qingyu
中科院分区：
文献类型：
--
作者：
Tan Chunlei;Wang Na;Pan Qichang;Li Yan;Li Yu;Ji Qiannan;Fan Xiaoping;Zheng Fenghua;Wang Hongqiang;Li Qingyu
为了提高LiNi0.5Mn1.5O4(LNMO)正极材料的电化学性能，将丁酸酐(BA)作为一种有效的功能添加剂。加入0.5wt%BA后，LNMO/Li电池在1C循环200次后的容量保持率从15.3%提高到88.4%。此外，LNMO/Li电池的倍率性能也得到了有效的提高，即使在5 C下容量也达到了112mAhg(-1)，大大高于没有添加BA的电解液中的LNMO/Li电池(5C时的容量为95.4mAhg(-1))。线性扫描伏安法和循环伏安法结果表明，BA添加剂可以优先被氧化，在LNMO阴极上形成稳定的阴极电解质界面(CEI)膜。随后，BA衍生的CEI膜可以减缓电解液的分解和LNMO正极中的Mn和Ni离子的溶解，并在循环过程中保持LNMO的结构稳定性，这使得LNMO具有优异的电化学性能。因此，本工作为高压LNMO基锂离子电池提供了一种高效、低成本的功能电解液。
Butyric anhydride (BA) is used as an effective functional additive to improve the electrochemical performance of a high-voltage LiNi0.5Mn1.5O4(LNMO) cathode. In the presence of 0.5 wt % BA, the capacity retention of a LNMO/Li cell is significantly improved from 15.3 to 88.4 % after 200 cycles at 1 C. Furthermore, the rate performance of the LNMO/Li cell is also effectively enhanced, and the capacity goes up to 112 mAh g(-1)even at 5 C, which is considerably higher than that of a LNMO/Li cell in electrolyte without BA additive (95.4 mAh g(-1)at 5 C). Linear sweep voltammetry and cyclic voltammetry results reveal that the BA additive can be preferentially oxidized to construct a stable cathode electrolyte interphase (CEI) film on the LNMO cathode. Subsequently, the BA-derived CEI film can alleviate the decomposition of the electrolyte and the dissolution of Mn and Ni ions from the LNMO cathode as well as maintain the structural stability of LNMO during the cycling process; this leads to outstanding electrochemical performance. Thus, this work provides an effective and low-cost functional electrolyte for high-voltage LNMO-based LIBs.