An Fuqiang, Zhang Rui, Wei Zhiguo, Li Ping
Beijing University of Science and Technology No.30 Collage Road, Haidian District Beijing China
Shanxi Changzheng Power Technology Co., Ltd. Shanxi China.
RSC Adv. 2019 Jul 10;9(37):21498-21506. doi: 10.1039/c9ra03629f. eCollection 2019 Jul 5.
A novel multi-stage-constant-current (MS-CC) charging protocol, which charges high-energy-density lithium-ion cells (LICs) at a faster rate, is presented herein. In this work, the 0-80% state of charge (SoC), according to the maximum charging rate, yields acceptable results for different SoCs, and the charging process is divided into three parts. Twelve groups of experiments are designed under the desired conditions of avoiding lithium plating and using a charging time of less than 36 min, and 1.5C constant current charging is used as a comparison experiment. The full pouch cells are dismantled, and the lithium deposition after 1.5C charging is more extensive than that after the MS-CC charging protocol. In addition, the capacity retention for 1.5C charging is 95.7%, while those for the 12 MS-CC charging protocol groups are within the range of 99.5-100.0% after the 300th cycle at 25 °C. When the temperature is 25 °C and 50 °C, the capacity retention of the 12 MS-CC charging protocol groups remains similar, but when the temperature drops to 10 °C, the capacity retention decreases except for the 2.0-1.5-0.9C and 1.8-1.5-0.9C groups. At the 510th cycle, the capacity retention of the 2.0-1.5-0.9C and 1.8-1.5-0.9C groups is 99.6% and 99.9%, respectively; the values of the other 10 groups are between 95.0% and 98.2%. The excellent electrochemical performances of the MS-CC charging protocol may be due to the minimal damage of cell materials caused by the step-type high-rate charging process; thus, the degree of polarization is small. Furthermore, compared with the conventional constant constant-current (CC) charging procedure, MS-CC charging greatly shortens the charging time.
本文提出了一种新型的多阶段恒流（MS-CC）充电协议，该协议能够以更快的速度对高能量密度锂离子电池（LIC）进行充电。在这项工作中，根据最大充电速率，0-80%的充电状态（SoC）对于不同的SoC产生了可接受的结果，并且充电过程分为三个部分。在避免锂镀层且充电时间小于36分钟的期望条件下设计了十二组实验，并将1.5C恒流充电用作对比实验。将完整的软包电池拆解后发现，1.5C充电后的锂沉积比MS-CC充电协议后的锂沉积更广泛。此外，1.5C充电的容量保持率为95.7%，而在25℃下经过第300次循环后，12个MS-CC充电协议组的容量保持率在99.5%-100.0%范围内。当温度为25℃和50℃时，12个MS-CC充电协议组的容量保持率保持相似，但当温度降至10℃时，除了2.0-1.5-0.9C和1.8-1.5-0.9C组外，容量保持率均下降。在第510次循环时，2.0-1.5-0.9C和1.8-1.5-0.9C组的容量保持率分别为99.6%和99.9%；其他10组的值在95.0%至98.2%之间。MS-CC充电协议优异的电化学性能可能归因于阶梯式高率充电过程对电池材料造成的损伤最小；因此，极化程度较小。此外，与传统的恒流（CC）充电程序相比，MS-CC充电大大缩短了充电时间。
