一种新型水系锌离子电池正极材料NiCo_(2)O_(4)的制备和电化学性能

Preparation and electrochemical properties of NiCo_(2)O_(4) as a novel cathode material for aqueous zinc-ion batteries

水系锌离子电池的能量密度高、稳定性好、安全系数高。NiCo_(2)O_(4)材料作为双过渡金属氧化物,其导电性能和电化学活性都很出色,本工作首次采用NiCo_(2)O_(4)材料作为水系锌离子电池的正极。采取了溶胶-凝胶法加煅烧热方法制备出立体尖晶石状的NiCo_(2)O_(4)材料,借助扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能谱分析技术(EDS)和电化学技术等表征测试手段,分析这种新型水系锌离子电池正极材料的形貌和电化学性能。结果表明,立体尖晶石状的NiCo_(2)O_(4)材料有着优良的纯度和结晶性,颗粒分散均匀,没有团聚,无杂质且具有良好稳定的充放电性能。电极在100 mA/g电流密度下,首次放电比容量为92 mA·h/g,100圈充放电测试后放电比容量为60 mA·h/g,200圈后,放电比容量保持在44 mA·h/g。但在循环倍率测试中发现,当电流密度较大时,NiCo_(2)O_(4)电极产生了27 mA·h/g的衰减,在一定程度上有着不可逆的冲击破坏。本研究有助于推动水性锌离子电池电极的应用,为高性能水性锌离子电池电极材料的研发提供实验依据。

Aqueous zinc-ion batteries have a high energy density,good stability,and high safety factor;as a double transition metal oxide,NiCo_(2)O_(4) has excellent electrical conductivity and electrochemical activity.Therefore,herein,NiCo_(2)O_(4) was novelly used as a novel cathode material for aqueous zinc-ion batteries.The solid spinel NiCo_(2)O_(4) material was prepared by the sol-gel and calcination heat methods.Using scanning electron microscopy,transmission electron microscope,energy dispersive spectroscopy,and electrochemical technology,the morphology and electrochemical properties of the cathode material of the new aqueous zinc-ion batteries were analyzed.The results show that the spinel NiCo_(2)O_(4) material has excellent purity and crystallinity,and the particles are evenly dispersed without agglomeration and impurity.Moreover,it has good and stable chargedischarge performance.At a current density of 100 mA·g^(-1),the initial specific discharge capacity of the electrode is 92 mA·h·g^(-1),60 mA·h·g^(-1) after 100 cycles,and 44 mA·h·g^(-1) after 200 cycles.However,when the current density is high,the specific capacitance of the NiCo_(2)O_(4) electrode decreases by 27 mA·h·g^(-1),which has irreversible impact damage to a certain extent.This study highlights that NiCo_(2)O_(4) material improves the performance of aqueous zinc-ion batteries,which can guide the future design of aqueous zinc-ion batteries.