Zheng Jiefeng, Wu Yuanji, Tong Yong, Sun Yingjuan, Li Hongyan
College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University, Guangzhou 510632, PR China.
College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University, Guangzhou 510632, PR China.
J Colloid Interface Sci. 2022 Sep 15;622:738-747. doi: 10.1016/j.jcis.2022.04.154. Epub 2022 May 2.
Antimony (Sb) has attracted considerable attention as an anode material for potassium ion batteries (PIBs) because of its high theoretical capacity. Nevertheless, owing to the large radius of K, apparent volume expansion occurs during the reaction between Sb and K, which will undermine the stability of the electrode. Accordingly, a dual-carbon confinement strategy is regarded as an effective method for handling this issue. Herein, Sb is firstly captured by mesoporous carbon sphere (MCS) to form a composite of Sb/MCS, and then reduced graphene oxide (rGO) is adopted as an outer layer to wrap the Sb/MCS to obtain the dual-carbon confinement material (Sb/MCS@rGO). Given the synergistic confinement effects of the MCS and rGO, the Sb/MCS@rGO electrode realizes an excellent rate capacity of 341.9 mAh g at 1000 mA g and prominent cycling stability with around 100% retention at 50 mA g after 100 cycles. Besides, the discussion on galvanostatic charge-discharge test, cyclic voltammetry and ex-situ XRD illustrates the stepwise potassium storage mechanism of Sb. Benefiting from the dual-carbon confinement effects, the Sb/MCS@rGO electrode processes promising electrochemical reaction kinetics. Furthermore, the application of the Sb/MCS@rGO in full cells also demonstrates its superior rate capacity (212.3 mAh g at 1000 mA g).
锑（Sb）因其高理论容量，作为钾离子电池（PIBs）的负极材料受到了广泛关注。然而，由于钾离子半径较大，锑与钾反应时会发生明显的体积膨胀，这将破坏电极的稳定性。因此，双碳限域策略被认为是解决这一问题的有效方法。在此，首先用介孔碳球（MCS）捕获锑形成Sb/MCS复合材料，然后采用还原氧化石墨烯（rGO）作为外层包裹Sb/MCS，得到双碳限域材料（Sb/MCS@rGO）。鉴于MCS和rGO的协同限域效应，Sb/MCS@rGO电极在1000 mA g下实现了341.9 mAh g的优异倍率性能，并且在50 mA g下循环100次后具有约100%的保留率，展现出突出的循环稳定性。此外，通过恒电流充放电测试、循环伏安法和非原位XRD的讨论，阐明了锑的分步储钾机制。受益于双碳限域效应，Sb/MCS@rGO电极具有良好的电化学反应动力学。此外，Sb/MCS@rGO在全电池中的应用也展示了其优异的倍率性能（在1000 mA g下为212.3 mAh g）。
