Enhancing the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 cathodes through amorphous coatings
Enhancing the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 cathodes through amorphous coatings
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DOI：
10.1016/j.electacta.2022.140745
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发表时间：
2022-06
影响因子：
6.6
通讯作者：
L. Dou;A. Tang;Wei-Chuang Lin;Xin Dong;Lu Lu-Lu;C. Shang;Zhanhui Zhang;Zhiliang Huang;K. Aifantis
中科院分区：
文献类型：
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作者：
L. Dou;A. Tang;Wei-Chuang Lin;Xin Dong;Lu Lu-Lu;C. Shang;Zhanhui Zhang;Zhiliang Huang;K. Aifantis
LiNi0.8Co0.1Mn0.1O2(NCM811)阴极因其较高的容量和工作电压而受到汽车行业的关注。尽管这些材料具有良好的电化学性能，但它们并不具有稳定的循环性能，因为它们与电解液接触时会发生寄生反应。因此，采用非晶态Nb2O5作为多功能保护层来稳定NCM811界面，从而减少了表面污染(Li2CO3)，减缓了过渡金属(TM)离子的溶解，并抑制了循环过程中的表面腐蚀和相变。结果表明，经200次循环后的NCM811的容量为180mAhg−1，容量保持率为85.7%，比未包覆样品的容量保持率提高30%。同样，Nb2O5涂层允许在5℃下的倍率容量提高到139mAhg−1，而纯−811的倍率容量为117.6 mAhg NCM1。此外，Nb2O5涂层有效地抑制了循环电压的衰减，200次循环后的电压衰减为70 mV，而在没有涂层的情况下，电压衰减降低了190 mV。
LiNi0.8Co0.1Mn0.1O2(NCM811) cathodes have attracted the attention of the automotive industry due to their higher capacity and operating voltage. Despite their promising electrochemical behavior, these materials do not have a stable cycling performance, as parasitic reactions take place when they come in contact with the electrolyte. Herein, amorphous Nb2O5is applied as a multifunctional protective layer to stabilize the NCM811 interface, resulting in reduced surface contamination (Li2CO3), alleviation of transition metal (TM) ion dissolution, and suppression of surface corrosion and phase transformations during cycling. As a result, after 200 cycles, the coated NCM811 had a capacity of 180 mAh g−1displaying an excellent capacity retention of 85.7%, which is 30% higher than that of the uncoated samples. Similarly, the Nb2O5coating allows for an enhanced rate capacity of 139 mAh g−1at 5 C, compared to 117.6 mAh g−1for the pure NCM811. In addition, the Nb2O5coating effectively suppresses the voltage decay with cycling, resulting in a voltage decay of 70 mV after 200 cycles, while a reduction of 190 mV takes place without the coating.