硼氮共掺杂海藻酸钠基多孔炭及其快速高效储锌

Boron and nitrogen co-doped sodium alginate-based porous carbons for durable and fast Zn-ion hybrid capacitors

近年来,锌离子电容器(ZIHCs)因其环境友好性和优异的电化学性能而备受关注。然而,ZIHCs的研究体系尚不成熟,为改善ZIHCs的储能动力学和循环稳定性等问题,亟需研发出低成本和高性能的碳基电极材料。本工作以海藻酸钠为碳前驱体,五硼酸铵为氮源和硼源,采用一步水热活化策略合成了氮/硼含量较高的分级多孔炭(NBSPC)。这种策略可以有效重塑炭的多孔结构,产生大量的活性位点,贡献额外的赝电容,从而提高其电化学性能。以NBSPC为正极构建了锌离子电容器,其在40 A g^(-1)的超高电流密度下,可以实现85.4 mAh g^(-1)优异的倍率性能,并在10 A g^(-1)的电流密度下可以稳定循环15000次,容量保持率高达94.5%。

In recent years,zinc-ion hybrid capacitors(ZIHCs)have attracted increasing attention due to their environmental friendliness and excellent electrochemical properties.However,their performance is mainly limited by the electrochemical perform-ance of the cathode,so it is necessary to develop an advanced cathode material.N,B co-doped sodium alginate-based porous carbon(NBSPC)was prepared by one-step co-carbonization using sodium alginate as the matrix and NH4B5O8 as the N and B source.This N,B co-doping strategy improves the pore structure of the carbon materials and increases the number of surface functional groups,greatly improving the capacitive behavior of the raw materials and thus improving their electrochemical performance.When used as the cathode in ZIHCs,the NBSPC had an excellent rate performance(85.4 mA h g^(-1)even at ultra-high current density of 40 A g^(-1))and good cycling stability(15000 cycles at 20 A g^(-1)with a capacity retention rate of 94.5%).