Owing to its ultra-high specific capacity, lithium metal holds great promise for revolutionizing current rechargeable battery technologies. Nevertheless, the unavoidable formation of dendritic Li, as well as the resulting safety hazards and poor cycling stability, have significantly hindered its practical applications. A mainstream strategy to solve this problem is introducing porous media, such as solid electrolytes, modified separators, or artificial protection layers, to block Li dendrite penetration. However, the scientific foundation of this strategy has not yet been elucidated. In this presentation, I am going to discuss the role of the porous media in suppressing dendritic Li growth and probe the underlying fundamental mechanisms based on experiments and simulation. It is found that the tortuous pores of the porous media, which drastically reduce the local flux of Li<sup>+</sup> moving towards the anode and effectively extend the physical path of dendrite growth, are the key to achieving the non-dendritic Li growth. Based on the theoretical exploration, we synthesize a novel porous silicon nitride submicron-wire membrane and incorporate it in both half-cell and full-cell configurations. The operation time of the battery cells is significantly extended without a short circuit. The findings lay the foundation to use a porous medium for achieving non-dendritic Li growth in Li metal-based batteries.

Suppressing dendritic lithium formation in lithium metal batteries

2019 Spring National Meeting

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