The noteworthy benefits of zero-excess sodium metal batteries (ZSMBs) regarding their energy density, sustainability, carbon footprint and cost make them a promising supplement or even substitute for lithium-ion batteries. Nevertheless, zero-excess sodium plating/stripping on an anode substrate encountered with sodium dendrite growth, inactive sodium generation and irreversible solid electrolyte interphase (SEI) formation make the improvement of the cycling stability of ZSMBs challenging. Herein, we discovered that structural instability and insufficient sodophilicity of the substrate interface are critical factors causing the irreversible sodium plating/stripping. Then, a microalloying welding strategy modified by nano-zinc coating was proposed to construct sodophilic interfaces and form a thin and robust organic/inorganic hybrid SEI in situ. This unique interface enables highly reversible sodium plating/stripping by improving the kinetic behavior of ion/electron exchange at the interface. Ultimately, ZSMBs assembled using this modified substrate with a highly loaded Na₃V₂(PO₄)₃ (NVP) cathode (∼10.4 mg cm⁻²) can deliver 90.5% initial coulombic efficiency and cycling stability for more than 800 times at an average decay rate of 0.041% per cycle. More importantly, the microalloying welding approach delineated in this study offers valuable insights into the attainment of a robust sodophilic interface. This study proposes that overcoming the poor reversibility issue of sodium plating/stripping in ZSMBs requires attention not only to the substrate sodophilicity, but also to the stability of the interfacial structure and the characteristics of the SEI.

中文翻译：

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用于高度可逆零过量钠金属电池的微合金化诱导稳定焊接界面


零过量钠金属电池（ZSMB）在能量密度、可持续性、碳足迹和成本方面具有显着的优势，使其成为锂离子电池的有前途的补充甚至替代品。然而，阳极基底上的零过量钠电镀/剥离会遇到钠枝晶生长、不活泼的钠生成和不可逆固体电解质中间相（SEI）形成，这使得提高ZSMB的循环稳定性具有挑战性。在此，我们发现结构不稳定性和基底界面的亲碱性不足是导致不可逆钠沉积/剥离的关键因素。然后，提出了一种通过纳米锌涂层改进的微合金化焊接策略，以构建亲碱界面并原位形成薄而坚固的有机/无机混合SEI。这种独特的界面通过改善界面处离子/电子交换的动力学行为，实现高度可逆的钠电镀/剥离。最终，ZSMB 使用这种改性基底与高负载 Na ₃ V ₂ (PO ₄ ) ₃ (NVP) 阴极组装而成（ ∼10.4 mg cm ⁻² ）可以提供 90.5% 的初始库仑效率和超过 800 次的循环稳定性，每次循环的平均衰减率为 0.041%。更重要的是，本研究中描述的微合金化焊接方法为实现坚固的嗜酸界面提供了宝贵的见解。本研究提出，克服ZSMB中钠电镀/剥离的可逆性差的问题不仅需要关注基材的亲碱性，还需要关注界面结构的稳定性和SEI的特性。