水系锌离子电池正极材料碲化铋层间质子可逆输运的原位观测

In-situ observation of reversible proton transport through Bi_(2)Te_(3) anode of aqueous zinc-ion battery

可充电水系锌离子电池因具备低成本、高安全性、无毒环保等优点备受关注,具有高比容量和工作电压的新型正极材料则是水系锌离子电池研究的热点之一,而碲化铋正是这样一种新兴材料。本工作采用一步水热法剥离碲化铋(Bi_(2)Te_(3))粉末获得稳定的碲化铋纳米结构材料,并首次探索将其作为正极材料应用于水系锌离子电池中。扫描电镜和原子力显微镜测试结果均表明合成的碲化铋具有纳米片形貌,厚度仅为3~5 nm。为了进一步深入研究其反应机理,利用同步辐射原位X射线衍射技术,实时表征碲化铋纳米片正极在电池充放电过程中的微观结构变化,并实时观察到碲化铋纳米片反应过程中高度可逆的质子插层现象,证实了质子在碲化铋正极材料中的可逆输运特性。

[background]The rechargeable aqueous zinc-ion batteries have attracted increasing attention due to their low cost,high safety,non-toxicity and environmental protection.The exploitation of new anode materials with high specific capacity and working voltage is one of research hotspots of aqueous zinc-ion battery whilst bismuth telluride is such an emerging materials.[Purpose]This study aims to observe the reversible proton transport in Bi_(2)Te_(3) anode of aqueous zinc-ion battery.[Method]First of all,bismuth telluride nanostructure was obtained by one-step hydrothermal exfoliating of bismuth telluride powder,and the bismuth telluride nanostructure was applied first time as anode material to aqueous zinc-ion battery.Then,both the scanning electron microscopy(SEM)and atomic force microscopy(AFM)were employed to oberve the nanosheets morphology and measure the thickness of synthesized Bi_(2)Te_(3) nanosheets.Finally,in-situ synchrotron radiation X-ray diffraction(XRD)technique was used to track the changes of structure of Bi_(2)Te_(3) nanosheets during the charge-discharge process of the battery.[Result]The thickness of synthesized Bi_(2)Te_(3) nanosheets measured by AFM is about 3~5 nm,and a highly reversible proton intercalation disclosed by in-situ synchrotron radiation based XRD during the reaction process is responsible for the practical battery operation.[Conclusions]This study confirms the reversible transport properties of protons in bismuth telluride cathode materials.