Sodium-metal batteries (SMBs) offer substantial competitiveness owing to their wide elemental distribution and high specific capacity. However, SMBs face safety issues such as unstable properties of the Solid Electrolyte Interphase (SEI) layer due to irregular sodium dendrites. In this paper, we constructed a stable and uniform SEI layer by introducing the 1,3,6-Hexanetricarbonitrile (HTCN) electrolyte additive, replacing the conventional, insoluble nitrate. HTCN facilitates the generation of substances like Na3N with high electrical conductivity on the Na anode surface. This accelerates Na+ shuttling and provides high-flux nucleation sites. Molecular dynamics simulations were employed to elucidate the solvated structure of electrolyte and radial distribution of Na+ after HTCN addition. Moreover, in-situ optical microscopy revealed a stable and robust SEI layer, effectively inhibiting the disorderly growth of sodium dendrites. The superior cycling performance of the Na3V2(PO4)3 (NVP)/Na full cell further demonstrates the addition of HTCN.

中文翻译：

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1,3,6-六甲腈作为电解质添加剂抑制钠金属电池中的钠枝晶


钠金属电池（SMB）由于其广泛的元素分布和高比容量而具有巨大的竞争力。然而，中小企业面临着安全问题，例如由于不规则的钠枝晶导致固体电解质中间相（SEI）层性能不稳定。在本文中，我们通过引入1,3,6-己三甲腈（HTCN）电解液添加剂来取代传统的不溶性硝酸盐，构建了稳定且均匀的SEI层。 HTCN有利于在Na阳极表面生成Na3N等具有高导电性的物质。这加速了 Na+ 穿梭并提供高通量成核位点。采用分子动力学模拟来阐明添加 HTCN 后电解质的溶剂化结构和 Na+ 的径向分布。此外，原位光学显微镜显示出稳定而坚固的SEI层，有效抑制了钠枝晶的无序生长。 Na3V2(PO4)3 (NVP)/Na全电池优越的循环性能进一步证明了HTCN的添加。