模板遗传实现纳微双尺度有序化碳单元及其在紧凑电容储能中的应用

Nano/micro dual-scale ordered carbon units via template heredity toward compact capacitive energy storage

紧凑型超级电容器需要具有高体积能量和功率密度的高密度碳.然而,大多数传统的密度提升方案都是基于孔隙压缩,导致提高体积性能的同时过多地牺牲倍率性能.在此,本研究从碳单元有序堆叠的相反角度出发,提出了一种通过调节模板形貌在纳米和微米双尺度上压缩碳单元之间剩余孔隙的新策略(即一级碳纳米笼和二级由碳纳米笼组成的类碟状组装体的双尺寸排序).优化的纳微有序碳单元的电极密度高达1.08 g cm^(-3)(是商业活性炭的两倍);在离子液体中表现了创纪录的体积能量密度(79 Wh L^(-1))和功率容量(31 kW L^(-1)),以及出色的稳定性(>30,000次循环)和理想的库仑效率(~100%).即使在商业级电极厚度下,其可用的最大堆叠功率密度仍然高达12 kW L^(-1),远高于大多数报道的致密碳.如此出色的体积性能使其在同时需要高体积能量和功率密度的领域具有巨大潜力.

High-density carbon with high volumetric energy and power densities is desired for compact supercapacitors.However,most of the traditional solutions for boosting density are based on pore regulation,resulting in an unreasonable sacrifice of rate performance.Herein,from an opposite perspective of carbon units’orderly stacking,a new strategy for compressing surplus pores between dual-scale carbon units at nanometer and micrometer scales(i.e.,two-stage ordering of the first-level carbon nanocages and the second-level micro disc-like carbon nanocage assemblies)has been developed by regulating the template.The optimized carbon packed with ordered nano-and micro-carbon units achieves a high density of 1.08 g cm^(-3)(two times that of the commercial activated carbon)and yields a record-high volumetric energy density(79 Wh L^(-1)),good power capability(31 kW L^(-1))in ionic liquid,superb stability(>30,000 cycles),and ideal Coulombic efficiency(~100%).Even at the commercial-level electrode thickness,the available maximal stack power density is still as high as 12 kW L^(-1),which is dramatically higher than most of the reported dense carbon.This excellent volumetric performance highlights its practical potential in areas that require high volume energy and power density simultaneously.