高性能柔性锌离子电池研究取得新进展
时间:2021-04-12


近日,我院陈浩教授带领的先进材料与绿色催化团队在高性能柔性锌离子电池研究领域取得新进展,相关成果以“Electrochemical Generation of Hydrated Zinc Vanadium Oxide with Boosted Intercalation Pseudocapacitive Storage for High-Rate Flexible Zinc Ion Battery”为题发表在国际材料期刊《ACS Applied Materials & Interfaces》上。论文第一作者为理学院硕士研究生陶园学,通讯作者为陈浩教授和罗艳珠副教授。

柔性可穿戴器件以其轻质、灵活柔韧和智能高效等优势将为可穿戴领域带来变革式的发展。由于大部分的柔性可穿戴设备的驱动力为电能,因此其柔性驱动电源的性能对于该领域的发展具有举足轻重的作用,而柔性驱动电源必须具有柔韧性好、小巧、超薄和体积能量密度高的特点才能更好的提升柔性可穿戴设备的性能。

由于双电子转移反应的水系锌离子电池具有价格低廉、无毒、资源丰富(锌元素丰度是锂元素的300倍)、安全性高、质量比容量(820 mA h g-1)和体积比容量(5855 mA h cm-3)高的特点,我院陈浩教授科研团队通过在电化学过程中水合二氧化钒/碳布(VOH/CC)材料的原位转化,获得柔性碱式钒酸锌/碳布(ZnVOH/CC)材料。这主要归因于电化学过程中部分H+Zn2+发生了不可逆脱嵌,使得初始的VOH/CC逐渐转变为ZnVOH/CC电极材料。ZnVOH/CC材料独特的结构优势主要体现在以下几个方面:(1)碳布和纳米片结构可实现材料与电解液的充分接触,从而实现快速的载流子传质过程;(2)结晶水、层间锌离子和晶格缺陷的存在增加了活性物质的电导率和反应位点,从而实现了具有高能量/功率密度的插层赝电容储能机理;(3)活性物质与碳布之间的结合力强,可有效减少活性物质在电化学过程中的团聚和溶解。

基于以上协同作用,ZnVOH/CC0.5 A g-1电流密度下具有337 mA h g-1的高放电容量,在20 A g-1电流密度下具有135 mA h g-1的超稳定可逆容量,并在5000次循环后未发生衰减。将ZnVOH/CCZn/CC负极组装成柔性器件,该柔性器件表现出优异的倍率性能和循环稳定性(在10 A g-1电流密度下循环170次后具有184 mA h g-1的可逆容量)。电池在折叠和打孔的情况下均可正常工作,表明它具有出色的柔性和安全性。上述研究工作通过电化学原位转化策略构建了高性能柔性锌离子电池电极,可为优化下一代水系锌离子电池电极材料的性能开拓新思路。

研究成果获得国家自然科学基金及湖北省自然科学基金项目资助。

论文链接:https://pubs.acs.org/doi/10.1021/acsami.1c03194

【英文摘要】 With the surging development of flexible wearable and stretchable electronic devices, flexible energy storage devices with excellent electrochemical property are in great demand. Herein, a flexible Zn-ion battery comprised of hydrated zinc vanadium oxide /carbon cloth (ZnVOH/CC) as the cathode is developed, and it shows a high energy density, superior lifespan, and good safety. The ZnVOH/CC is obtained by the in-situ transformation of hydrated vanadium oxide/carbon cloth (VOH/CC) by electrochemical method, and the intercalation pseudocapacitive reaction mechanism is discovered for ZnVOH/CC. The co-insertion/deinsertion of H+/Zn2+ is observed, the H+-insertion dominates in the initial discharge stage and high-rate electrochemical process, while Zn2+-insertion dominates the following discharge stage and low-rate electrochemical procedure. An ultra-stable reversible capacity of 135 mA h g-1 at 20 A g-1 is obtained after 5000 cycles without capacity fading. Moreover, the as-assembled flexible zinc-ion battery can operate normally under rolled, folded, and punched conditions with superior safety. It is capable to deliver a high discharge capacity of 184 mA h g-1 at 10 A g-1 after 170 cycles. This work paves a new way for designing low-cost, safe, and quick charging energy storage devices for flexible electronics.

通讯员:罗艳珠

审核人:陈