水系铵离子电池β-MnO_(2)正极材料的制备及性能研究

Research on Preparation and Performance ofβ-MnO_(2) Cathode Material for Aqueous Ammoniumion Battery

通过简单的水热法合成了隧道型β-MnO_(2)正极材料并应用于水系铵离子电池,并采用1 mol/L(NH4)2SO4水系电解液,在窗口电压为0~1.6 V范围内,测试其电化学性能。实验结果表明:β-MnO_(2)正极材料在0.1A/g电流密度下表现出109.8 mAh/g放电比容量,经过140次循环后,其放电比容量仍有101.9 mAh/g,容量保留率为92.8%,库伦效率接近100%,具有优异的循环稳定性能。同时还具有优异的倍率性能,β-MnO_(2)纳米棒正极材料即使在1.0 A/g大电流密度下仍有78.7 mAh/g。此外,通过非原位FTIR、XPS测试探索了其储铵机理,结果表明铵根离子具有良好的可逆性。

Tunnel-typeβ-MnO_(2) cathode materials are synthesized by adopting simple hydrothermal method with its application to aqueous ammoniumion batteries,shows excellent electrochemical performance within a voltage window range of 0~1.6 V by using 1 mol/L(NH4)2SO4 aqueous electrolyte.The experimental results show thatβ-MnO_(2) cathode materials exhibit a discharge specific capacity of 109.8 mAh/g at a current density of 0.1 A/g.After 140 cycles,its discharge specific capacity still reaches as high as 101.9 mAh/g,with a capacity retention rate of 92.8%and a Coulombic efficiency close to 100%,demonstrating an excellent cycling stability.Meanwhile,β-MnO_(2) nanorod cathode material is characterized with an excellent rate performance,with a discharge specific capacity of 78.7 mAh/g at a high current density of 1.0 A/g.In addition,an inquiry has been made into the energy storage mechanism based on ex situ FTIR and XPS testing,with the results showing that the ammoniumions exhibiting a good reversibility.