In situ healing of dendrites in a potassium metal battery
In situ healing of dendrites in a potassium metal battery
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DOI：
10.1073/pnas.1915470117
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发表时间：
2020-03-17
影响因子：
11.1
通讯作者：
Koratkar, Nikhil
中科院分区：
文献类型：
--
作者：
Hundekar, Prateek;Basu, Swastik;Koratkar, Nikhil
钾（K）金属阳极的使用可以产生高性能的K离子电池，为锂（Li）离子技术提供可持续和低成本的替代品。然而，在这样的K金属表面上形成枝晶是不可避免的，这妨碍了它们的利用。在这里，我们报告说，K枝晶可以在原位愈合的K-金属电池。愈合是由电流控制的，在电解质/枝晶界面处的自加热触发的，这导致表面原子远离枝晶尖端的迁移，从而使枝晶表面平滑。我们发现，这个过程是惊人的更有效的K相比，金属锂。我们表明，这是因为K中的表面原子相对于Li金属具有更大的迁移率，这使得枝晶愈合能够在较低的电流密度下发生。我们证明了K-金属阳极可以与钾钴氧化物阴极耦合，以在实际的全电池设备中实现枝晶愈合。
The use of potassium (K) metal anodes could result in high-performance K-ion batteries that offer a sustainable and low-cost alternative to lithium (Li)-ion technology. However, formation of dendrites on such K-metal surfaces is inevitable, which prevents their utilization. Here, we report that K dendrites can be healed in situ in a K-metal battery. The healing is triggered by current-controlled, self-heating at the electrolyte/dendrite interface, which causes migration of surface atoms away from the dendrite tips, thereby smoothening the dendritic surface. We discover that this process is strikingly more efficient for K as compared to Limetal. We show that the reason for this is the far greater mobility of surface atoms in K relative to Li metal, which enables dendrite healing to take place at an order-of-magnitude lower current density. We demonstrate that the K-metal anode can be coupled with a potassium cobalt oxide cathode to achieve dendrite healing in a practical full-cell device.