用于水锌电容的硝酸处理N掺杂碳材料的制备及其电化学性能

Preparation and Electrochemical Properties of Nitrate-Activated N-Doped Carbon Materials for Aqueous Zinc Capacitors

为了满足现代电子设备对储能装置快速充放电和长周期循环稳定性的需要,亟需开发新型的电化学储能装置,水系锌离子混合电容器(ZIHC)因其固有优势被认为是一种极具发展潜力的储能设备。为此,研制了一种由金属有机框架(MOF)衍生的N掺杂碳(N-C)材料作为ZIHC的高性能正极,并对其进行硝酸活化(N-C-HNO_(3))改性。实验结果表明,在0.2~1.8 V的电压窗口内,N-C-HNO_(3)在0.2 A·g^(-1)的电流密度下具有117.78 mA·h·g^(-1)的质量比容量,即使电流密度增大到10 A·g^(-1),质量比容量仍有52.78 mA·h·g^(-1)。20 000次充放电循环之后比电容保持率为103.83%。同时结合非原位表征技术揭示了ZIHC的Zn^(2+)、H^(+)和SO_(4)^(2-)的共吸附储能机制。基于硝酸对N掺杂碳材料进行处理,可以改善碳材料的电化学性质,能够显著提升ZIHC正极的电化学性能。

To meet the needs of modern electronic devices for fast charging and discharging and long cycle stability of energy storage devices,it is urgent to develop new types of electrochemical energy storage devices.And aqueous zinc-ion hybrid capacitors(ZIHCs)are considered to be a kind of energy storage devices with great development potential due to their inherent advantages.Thus,an N-doped carbon(N-C)material derived from metal-organic frameworks(MOFs)as a high-performance cathode for ZIHCs was developed and modified with nitric acid activation(N-C-HNO_(3)).The experimental results show that N-C-HNO_(3) has a mass specific capacity of 117.78 mA·h·g^(-1) at a current density of 0.2 A·g^(-1) within the voltage window of 0.2-1.8 V.Even when the current density increases to 10 A·g^(-1),the mass specific capacity is still 52.78 mA·h·g^(-1).After 20000 charging/discharging cycles,the specific capacitance retention is 103.83%.Meanwhile,the co-adsorption energy storage mechanism of Zn^(2+),H^(+) and SO_(2-)^(4) in ZIHCs was revealed by combining with non-in situ characterization technique.The treatment of N-doped carbon materials based on nitric acid can improve the electrochemical properties of carbon materials and significantly improve the electrochemical performance of ZIHCs cathodes.