Li Qian, Wang Tongde, Shu Tie, Pan Xiaoyi, Tao Yousheng
College of Materials Science and Engineering, Sichuan University, Chengdu, 610065, People's Republic of China.
Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China.
Nanoscale. 2024 Oct 17;16(40):19086-19099. doi: 10.1039/d4nr03032j.
Inheriting the energy storage mechanism of supercapacitors and rechargeable ion batteries, zinc ion capacitors (ZICs) greatly increase their energy density at high power without sacrificing their life span. However, sluggish kinetics and insufficient active sites for Zn storage induced by the significant mismatch of charge carriers with limited pore size hinder the efficient Zn storage and smooth application of carbonaceous cathode materials. Herein, a three-dimensional honeycomb-like porous carbon network (HPCN) was fabricated, which can reduce the diffusion barrier for fast kinetics, produce a high-density defect area, effectively increase active sites for charge storage, and generate a high nitrogen-doping content. Benefiting from these advantages, the optimized ZICs bring out a marvelous energy/power density (130 W h kg/11.7 kW kg) with an ultrahigh reliable cyclability of 97.8% after 50 000 cycles at a high current density of 5 A g. Importantly, systematic characterizations combined with theoretical calculations demonstrate that the outstanding Zn storage capacity is attributed to the synergistic effect of physical co-adsorption of cations and reversible chemisorption. This work presents an attractive strategy for developing advanced carbon cathodes with suitable pores and accelerates the exploration of charge storage mechanisms, which may open a new avenue for practical supercapacitors.
锌离子电容器（ZICs）继承了超级电容器和可充电离子电池的储能机制，在不牺牲其寿命的情况下，大大提高了其在高功率下的能量密度。然而，电荷载流子与有限孔径的显著不匹配导致锌存储的动力学缓慢和活性位点不足，这阻碍了含碳阴极材料的高效锌存储和顺利应用。在此，制备了一种三维蜂窝状多孔碳网络（HPCN），它可以降低快速动力学的扩散势垒，产生高密度缺陷区域，有效增加电荷存储的活性位点，并产生高氮掺杂含量。受益于这些优点，优化后的ZICs展现出出色的能量/功率密度（130 W h kg/11.7 kW kg），在5 A g的高电流密度下循环50000次后，具有97.8%的超高循环稳定性。重要的是，系统的表征与理论计算相结合表明，出色的锌存储容量归因于阳离子物理共吸附和可逆化学吸附的协同效应。这项工作为开发具有合适孔隙的先进碳阴极提出了一种有吸引力的策略，并加速了对电荷存储机制的探索，这可能为实用超级电容器开辟一条新途径。
