Nitrogen-rich hard carbon as a highly durable anode for high-power potassium-ion batteries
Nitrogen-rich hard carbon as a highly durable anode for high-power potassium-ion batteries
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富氮硬碳作为高功率钾离子电池的高度耐用阳极
DOI：
10.1016/j.ensm.2017.05.010
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发表时间：
2017-07-01
影响因子：
20.4
通讯作者：
Xie, Jia
中科院分区：
文献类型：
--
作者：
Chen, Chaoji;Wang, Zhenggang;Xie, Jia
碳质电极材料因其丰富的钾资源和合理的性能而备受关注。然而，它们的倍率性能和循环寿命主要受到插层化学的阻碍，所述插层化学涉及难以在短时间或长期循环内维持的重复钾插入/提取。在这里，第一次，海鲜废物（甲壳素）衍生的分级多孔氮掺杂碳微球（NCS）电极与表面驱动的钾存储机制的开发。NCS电极在72 C下表现出154 mA h g（-1）的创纪录的高倍率性能和4000次循环的超长循环寿命而没有明显的容量衰减（1.8 C下180 mA h g（-1）），代表了KIB中所有电极中最好的倍率性能和最长的循环寿命，甚至超过了钠离子电池（NIB）中的大多数电极。进一步的动力学分析和第一性原理计算揭示了NCS中主要的电容表面驱动的钾存储机制，这归因于分级多孔的微观结构和氮掺杂的碳结构，其具有增强的钾吸附能力和电子/离子电导率。
Carbonaceous electrode materials for potassium-ion batteries (KIBs) are attractive due to the abundant resource of potassium and their rational capability. However, their rate capability and cycle life are mainly hindered by the intercalation chemistry involving repeated potassium insertion/extraction that are difficult to maintain within a short time or long-term cycling. Here, for the first time, a seafood waste (chitin)-derived hierarchically porous nitrogen-doped carbon microsphere (NCS) electrode with a surface-driven potassium storage mechanism is developed. The NCS electrode demonstrates a record high rate capability of 154 mA h g(-1) at 72 C and ultralong cycle life of 4000 cycles without obvious capacity decay (180 mA h g(-1) at 1.8 C), representing the best rate capability and longest cycle life among all electrodes in KIBs and even supassing most electrodes in sodiumion batteries (NIBs). Further kinetic analysis and first-principle calculations reveal the dominated capacitive surface-driven mechanism of potassium storage in NCS, which is attributed to the hierarchically porous microstructure and nitrogen-doped carbon structure with enhanced potassium adsorption capability and electronic/ionic conductivities.