Impacts of negative to positive capacities ratios on the performance of next-generation lithium-ion batteries
Impacts of negative to positive capacities ratios on the performance of next-generation lithium-ion batteries
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负正容量比对下一代锂离子电池性能的影响
DOI：
10.1016/j.electacta.2022.139878
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发表时间：
2022
影响因子：
6.6
通讯作者：
Bai, Peng
中科院分区：
文献类型：
--
作者：
Mu, Ge;Agrawal, Shubham;Sittisomwong, Poom;Bai, Peng
负极和正极之间的容量比（N/P比）是设计高性能和安全锂离子电池的一个简单但重要的因素。然而，现有的研究主要集中在不同的N/P比的实验现象。详细的理论分析和物理解释尚待研究。本文通过物理建模和实验相结合的方法，研究了不同N/P比对硅石墨复合负极和LiNi 0. 8 Co 0. 1 Mn 0. 1 O2正极（Si-Gr/NMC 811）电池性能的影响。结果表明，较高的N/P比使更好的循环性能，而比例的选择是一个多方面的优化问题。在不同的氮磷比下，平衡开路电位和各种电化学极化的动态过电位都影响电极利用率。由于电极利用率相对于N/P比的相反趋势，需要借助数学模拟来优化电池，以确定最佳设计，而不是使用简单的N/P比1来满足特定需求。
The capacity ratio between the negative and positive electrodes (N/P ratio) is a simple but important factor in designing high-performance and safe lithium-ion batteries. However, existing research on N/P ratios focuses mainly on the experimental phenomena of various N/P ratios. Detailed theoretical analysis and physical explanations are yet to be investigated. Here, by combining physics-based modeling and experiments, quantitative understandings of the effects of different N/P ratios for batteries with the silicon-graphite composite anode and the LiNi0.8Co0.1Mn0.1O2cathode (Si-Gr/NMC811) are investigated. The results reveal that higher N/P ratios enabled better cycling performance, while the choice of the ratio is a multi-facet optimization problem. Both the equilibrium open-circuit potential and the dynamic overpotentials of various electrochemical polarization are found to affect the electrode utilization at different N/P ratios. Due to the opposite trends of electrode utilization with respect to the N/P ratio, batteries need to be optimized with the help of mathematical simulations to identify the best design, rather than using a simple N/P ratio of 1, to meet specific needs.