Guo Mingyi, Zhang Hao, Huang Zheng, Li Wenbin, Zhang Dingyue, Gao Caiqing, Gao Fan, He Ping, Wang Jiagui, Chen Weihua, Chen Xianchun, Terrones Mauricio, Wang Yanqing
College of Polymer Science and Engineering, Sichuan University, Chengdu, 610065, China.
College of Chemistry & Green Catalysis Center, Zhengzhou University, Zhengzhou, Henan, 450001, China.
Small. 2023 Sep;19(39):e2302583. doi: 10.1002/smll.202302583. Epub 2023 May 26.
The slow solid diffusion dynamics of sodium ions and the side-reaction of sodium metal plating at low potential in the hard carbon anode of sodium ion batteries (SIBs) pose significant challenges to the safety manipulation of high-rate batteries. Herein, a simple yet powerful fabricating method is reported on for "egg puff"-like hard carbon with few N doping using rosin as a precursor via liquid salt template-assisted and potassium hydroxide dual activation. The as-synthesized hard carbon delivers promising electrochemical properties in the ether-based electrolyte especially at high rates, based on the absorption mechanism of fast charge transfer. The optimized hard carbon exhibits a high specific capacity of 367 mAh g at 0.05 A g and 92.9% initial coulombic efficiency (ICE), 183 mAh g at 10 A g , and ultra-long cycle stability of reversible discharge capacity of 151 mAh g after 12,000 cycles at 5 A g with the average coulombic efficiency of ≈99% and the decay of 0.0026% per cycle. These studies will undoubtedly provide an effective and practical strategy for advanced hard carbon anode of SIBs based on adsorption mechanism.
钠离子在钠离子电池（SIBs）硬碳负极中的缓慢固体扩散动力学以及低电位下金属钠镀层的副反应，对高倍率电池的安全操作构成了重大挑战。在此，报道了一种简单而有效的制备方法，以松香为前驱体，通过熔盐模板辅助和氢氧化钾双重活化制备了少量氮掺杂的“蛋酥卷”状硬碳。基于快速电荷转移的吸附机制，所制备的硬碳在醚基电解质中尤其在高倍率下具有良好的电化学性能。优化后的硬碳在0.05 A g下表现出367 mAh g的高比容量和92.9%的初始库仑效率（ICE），在10 A g下为183 mAh g，在5 A g下经过12000次循环后，可逆放电容量为151 mAh g，具有超长的循环稳定性，平均库仑效率约为99%，每循环衰减0.0026%。这些研究无疑将为基于吸附机制的SIBs先进硬碳负极提供一种有效且实用的策略。
