Abstract The lifetime performance of lithium-ion batteries is a critical issue for automobile and stationary applications. The difference in the side-reaction current (ISR) of electrodes causes deviations of the state of charge (SOC) of the electrodes leading to the capacity fading of lithium-ion batteries. Establishment of a method to measure the ISR is important for understanding the capacity fading mechanism. We report herein that a novel and simple method to determine the ISR in lithium-ion batteries, the self-discharge test, was developed and applied to lithium-ion cells with lithium titanium oxide (Li[Li1/3Ti5/3]O4, LTO), lithium aluminum manganese oxide (Li[Li0.1Al0.1Mn1.8]O4, LAMO), and lithium nickel manganese oxide (Li[Ni1/2Mn3/2]O4, LiNiMO) as electrodes. According to the self-discharge test results, the ISR of LTO is affected by another electrode of LAMO or LiNiMO. The ISR of LTO in LTO/LiNiMO cells larger than that in LTO/LAMO cells is explained by the additional-ISR of LTO, which results from side reactions such as the reduction of oxidized products generated at the positive electrode. The side reactions at the positive electrode are accelerated with increasing electrode potential, meaning that the higher potential of the positive electrode resulted in the larger additional-ISR of LTO. The real side-reaction current of the LTO electrode in lithium-ion cells is the sum of the intrinsic and the additional current (real-ISR = intrinsic-ISR + additional-ISR).

中文翻译：

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测量 Li[Li1/3Ti5/3]O4 电极副反应电流的自放电测试

摘要 锂离子电池的寿命性能是汽车和固定应用的关键问题。电极侧反应电流（ISR）的差异会导致电极荷电状态（SOC）的偏差，导致锂离子电池容量衰减。建立测量 ISR 的方法对于理解容量衰减机制很重要。我们在此报告，开发了一种新颖且简单的方法来确定锂离子电池中的 ISR，即自放电测试，并将其应用于具有锂钛氧化物 (Li[Li1/3Ti5/3]O4, LTO )、锂铝锰氧化物 (Li[Li0.1Al0.1Mn1.8]O4, LAMO) 和锂镍锰氧化物 (Li[Ni1/2Mn3/2]O4, LiNiMO) 作为电极。根据自放电测试结果，LTO 的 ISR 受另一个 LAMO 或 LiNiMO 电极的影响。LTO/LiNiMO 电池中 LTO 的 ISR 大于 LTO/LAMO 电池，这是由 LTO 的附加 ISR 来解释的，这是由副反应引起的，例如正极产生的氧化产物的还原。正极的副反应随着电极电位的增加而加速，这意味着正极电位越高，LTO 的附加 ISR 越大。锂离子电池中 LTO 电极的实际副反应电流是本征电流和附加电流的总和（实际 ISR = 本征 ISR + 附加 ISR）。这是由副反应引起的，例如在正极产生的氧化产物的还原。正极的副反应随着电极电位的增加而加速，这意味着正极电位越高，LTO 的附加 ISR 越大。锂离子电池中 LTO 电极的实际副反应电流是本征电流和附加电流的总和（实际 ISR = 本征 ISR + 附加 ISR）。这是由副反应引起的，例如在正极产生的氧化产物的还原。正极的副反应随着电极电位的增加而加速，这意味着正极电位越高，LTO 的附加 ISR 越大。锂离子电池中 LTO 电极的实际副反应电流是本征电流和附加电流的总和（实际 ISR = 本征 ISR + 附加 ISR）。