在不同温度下的微锂离子电池快速充电

In a recent study published in theJournal of Colloid and Interface Science，研究人员首次在环境和高温条件下首次分析了微锂离子电池（LIB）的快速充电行为。

Study:The fast-charging properties of micro lithium-ion batteries for smart devices。Image Credit: ArnyGFX/Shutterstock.com

In this case, the electrochemical test results for 60 mAh LiCoO₂/在环境温度下的石墨电池表明，高于4C的充电速率（即4 A持续15分钟）导致电池容量的加速衰减，而充电时间没有明显减少。但是，在较高的温度为65℃的情况下，充电率提高到6C（即6 a 10分钟）。

快速充电和微型自由

由于能量和功率密度很高，尽管锂（Li）稀缺，但LIB将在未来几年中成为最高首选的电池系统。高能密度是指高存储容量，高功率密度是指更快的充电速率。

As per a recent report, US advanced battery Consortium (USABC) has a target to achieve a charge of 80% of the full capacity of a battery within 15 min for electric vehicles (EVs) by 2023. Micro-sized parallel LIB cells may offer a solution to achieve this high charging rate. However, their fast-charging properties under different temperature conditions are still an untouched research topic.

LIB容易在高温下生长和短路。同样，由于微型LIB单元，可能会触发几个不优先电池和充电条件，并导致热失控。热失控是一种链反应，其中Li金属/离子与大气中的氧气接触，并且由于多个触发因素而超过了一定的阈值能级，从而导致Libs迅速排出并引起火。此外，快速充电会导致LI电镀，大热产生，固体电解质界面（SEI）生长以及阴极的活性材料丢失。欧洲杯足球竞彩

关于研究

在这项研究中，研究人员制作了由1254型LiCoo组成的无线耳机₂/graphite micro-LIB cells and studied its electrochemical performance at ambient and elevated temperatures. Four charging rates viz. 1C, 2C, 3C, 4C, and 6C, and three temperatures viz. ambient (i.e., 25 ℃), 45 ℃, and 65 ℃ temperature conditions were incorporated into the test.

观察

For the first cycle and 60 mAh full capacity at ambient temperature conditions, the total charging capacities were 81.46%, 21.8%, and 9.25% under 1C, 4C, and 6C charging rates, respectively. The discharge profile was almost identical but, high current density resulted in increased polarization under limited mass transportation, which caused sluggish diffusion kinetics in graphite.

电池全容量的1C，2C和4C充电率分别为50、30和18分钟。令人惊讶的是，高于4C电荷率，充电持续时间没有降低。充电和排放能力随着充电率的增加而降低。此外，更快的充电率（即6C时）导致了快速的电池老化。

More from AZoM: The Use of AFM in Archaeology and Paleontology

The SEM images of the morphologies of LiCoO₂新鲜和快速充电周期后获得的4C充电率的电极相似，没有任何明显的裂纹。在4C充电速率和环境温度下，微纤维比高能量密度LIB具有出色的电化学性能。快速充电导致在甘田表面滑行的平面滑行₂electrode and led to exfoliation of graphite layers and incrassation of SEI film on the lithium surface.

在升高温度下，4C充电率的初始充电和排放能力为60、66和65 mAh，在25、45和65℃时为65 mAh。65℃时充电和放电容量的增加与整个电池的极化下降有关。但是，对于相同的温度，6C充电率导致电池容量衰减。

从the EIS results, it is evident that the resistance of SEI film increased with an increase in temperature. LiF was the major constituent compound of the formed SEI film on the graphite, which increased with an increase in temperature.

结论

总而言之，这项研究的研究人员编造了由licoo组成的微李子₂as the cathode and graphite as the anode material and studied their electrochemical performances under ambient (25 ℃) and elevated temperatures (45 and 65 ℃). Under ambient temperature, 4C was the optimal charging rate with the shortest charging time of 18 min, whereas the charging time can further decrease (i.e., charging rate increased to 6C) only when the temper went up to 65 ℃.

However, this fast charging at elevated temperature resulted in battery decay; the graphite electrode exfoliated and LiF SEI incrassated on the cathode LiCoO₂electrode.

资源

Gao，X.，Zhou，H.，Li，S.，Chang，S.，Lai，Y.，Zhang，Z.，智能设备的微锂离子电池的快速充电性能，Journal of Colloid and Interface Science，615，2022，141-150，0021-9797，https://www.sciencedirect.com/science/article/pii/S0021979722001187?via%3Dihub

免责声明：此处表达的观点是以其私人身份表达的作者的观点，不一定代表AZOM.com的观点有限的T/A Azonetwork本网站的所有者和运营商。此免责声明构成了条款和条件使用此网站。