Boosting the interface reaction activity and kinetics of cobalt molybdate by phosphating treatment for aqueous zinc-ion batteries with high energy density and long cycle life
Boosting the interface reaction activity and kinetics of cobalt molybdate by phosphating treatment for aqueous zinc-ion batteries with high energy density and long cycle life
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DOI：
10.1039/d0ta07746a
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发表时间：
2020-10-28
影响因子：
11.9
通讯作者：
Xu, Kaibing
中科院分区：
文献类型：
--
作者：
Shen, Yuenian;Li, Zhihao;Xu, Kaibing
作为便携式和可穿戴电子产品最可靠的电源之一，水性锌离子电池完全满足高安全性的要求，但其储能能力仍受到缺乏高性能正极材料的限制。在这项研究中，钴钼酸盐（CoMoO 4）纳米片的导电性差和缓慢的界面反应，很好地解决了一步磷化处理（表示为P-CoMoO 4），这是一个先进的阴极材料，可充电锌离子电池。首先，利用富集的氧空位精细地操纵电子结构，从而提高电子电导率和反应活性。此外，表面磷酸根离子的改性可以降低氧化还原反应所需的活化能，从而增加反应动力学。此外，丰富的金属CoP纳米颗粒均匀分布在CoMoO 4纳米片的基质中，促进了活性位点的暴露和界面反应。正如预期的那样，优化的P-CoMoO 4电极相对于原始CoMoO 4显示出上级的比容量（在10 A g（-1）下为431.4 mA h g（-1））和倍率性能（在50 A g（-1）下为43.8%容量保持率）。组装后的P-CoMoO 4//Zn电池在8.6kW·kg（-1）下的能量密度高达679.4W·h·kg（-1），并且具有超长的寿命（在60 mV·s（-1）下循环12000次后，初始容量保持率超过80%）。因此，本工作可能提供一个更好的选择，为高性能的阴极材料，为水溶液锌离子电池。
As one of the most reliable power sources for portable and wearable electronics, aqueous zinc-ion batteries fully meet the requirement of high safety, while their energy storage ability is still limited by the lack of high-performance cathode materials. In this study, the poor electrical conductivity and sluggish interface reaction of cobalt molybdate (CoMoO4) nanosheets are well addressed by one-step phosphating treatment (denoted as P-CoMoO4), which serve as an advanced cathode material for rechargeable zinc-ion batteries. Primarily, the electronic structures are finely manipulated using enriched oxygen vacancies, therefore improving the electronic conductivity and reaction activity. Moreover, the modification of surface phosphate ions can reduce the required activation energy for redox reactions and consequently increase the reaction kinetics. Additionally, abundant metallic CoP nanoparticles are uniformly distributed in the matrix of CoMoO4 nanosheets, boosting the exposure of active sites and interface reactions. As expected, the optimized P-CoMoO4 electrode shows a superior specific capacity (431.4 mA h g(-1) at 10 A g(-1)) and rate performance (43.8% capacity retention at 50 A g(-1)) relative to pristine CoMoO4. Furthermore, the assembled P-CoMoO4//Zn battery exhibits a remarkable energy density of 679.4 W h kg(-1) at 8.6 kW kg(-1), and an ultra-long life span (over 80% retention of the initial capacity after 12 000 cycles at 60 mV s(-1)). Hence, this work may offer a preferable option for high-performance cathode materials for aqueous zinc-ion batteries.