基于二维多孔有机聚合物制备二维功能化富炭材料的普适性策略及双炭锂离子电容器应用

A universal strategy for producing 2D functional carbon-rich materials from 2D porous organic polymers for dual-carbon lithium-ion capacitors

二维炭材料引起了研究人员广泛的关注,然而,其复杂的合成方法、非均匀的结构以及难以精确控制的性质限制了这一形貌控制科学的发展。本研究开发了一种普适性的制备方法,通过简便的化学交联反应,利用吡咯和吲哚作为氮源,3,4-乙烯二氧噻吩作为硫源,制备了一系列杂原子掺杂的二维多孔聚合物。这种自下而上的策略能够实现高杂原子含量、丰富孔性结构和超薄厚度的功能化炭纳米片的大规模合成。因此,所得到的氮掺杂炭纳米片作为锂离子电容器负极,在5 A g^(-1)条件下表现出573.4 mAh g^(-1)的比容量,而经优化的氮掺杂炭纳米片作为锂离子电容器正极,在5 A g^(-1)条件下表现出100.0 F g^(-1)的比电容。基于此,开发了一种双碳离子电容器,在400 W kg^(-1)条件下,168.4 Wh kg^(-1)的能量密度,循环10000次后循环稳定性保持在86.3%。值得注意的是,这种自下而上的策略为大规模精确定制具有目标结构和性质的二维功能化炭纳米片开辟了新途径。

Two-dimensional(2D)carbon materials have attracted enormous attention,but the complicated synthesis methods,inhomogeneous structure and uncontrollable properties still limit their use.Here we report a universal protocol for fabricating a series of heteroatom-doped 2D porous polymers,including pyrrole and indole as nitrogen-dopant sources,and 3,4-ethoxylene dioxy thiophene as a sulfur-dopant source by a simple chemical crosslinking reaction.This bottom-up strategy allows for the large-scale synthesis of functionalized ultrathin carbon nanosheets with a high heteroatom doping content and abundant porosity.Consequently,the obtained N-doped carbon-rich nanosheets(NCNs)sample has a specific capacity of 573.4 mAh g^(-1)at 5 A g^(-1)as an anode for lithium-ion capacitors(LICs),and the optimized sample has a specific capacitance of 100.0 F g^(-1)at 5 A g^(-1)when used as a cathode for a LIC.A dual-carbon LIC device was also developed that had an energy density of 168.4 Wh kg^(-1)at 400 W kg^(-1),while maintaining outstanding cycling stability with a retention rate of 86.3%after 10000 cycles.This approach has the potential to establish a way for the precise synthesis of substantial amounts of 2D functionalized carbon nanosheets with the desired structure and properties.