The wide application of high-energy all-solid-state lithium metal batteries (AS-LMBs) is still challenging due to their dendrite growth at anode, high interfacial resistance and low cathode loading. Herein, a dual conversion reaction strategy is proposed to construct a compact multiple heterostructure interface with mixed ion/electron conductive (MIEC) domains. The obtained LiF/Cu–Mo MIEC layer can inhibit Li dendrite growth and reduce interfacial resistance by regulating the diffusion and migration of the charged species at the heterogeneous interfaces. Additionally, a hot melt-penetration-bonding process of ionic wires is developed to address the issues of high contact impedance at the cathode/garnet interface and insufficient conduction in the bulk cathode, allowing full cells to function normally without adding any ionic liquid/electrolyte wetting agent. It enables the construction of a high-loading cathode with continuous Li-ion transport channels and intimate contact with the garnet electrolyte. Thus, the Li symmetric cells exhibit stable cycling for more than 10 000 h without short-circuiting at 0.2 mA cm⁻², with a low overpotential of only ∼10 mV and ultrahigh cumulative capacity close to 2.5 A h cm⁻². The all-solid-state conversion reaction batteries, with a high mass loading of FeF₃ cathode up to 6 mg cm⁻², achieve a high specific capacity of 300 mA h g⁻¹ after 300 cycles at 0.3C. The reversible capacity still exceeds 250 mA h g⁻¹ even under an ultrahigh current density of 712 mA g⁻¹. This study demonstrates a dual fluorination effect on both anode and cathode sides to develop high-capacity AS-LMBs based on the conversion cathode systems.

中文翻译：

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异质结构导电界面和熔融渗透键合工艺，可提供具有高阴极负载的全固态 Li-FeF3 石榴石电池


高能全固态锂金属电池 （AS-LMB） 的广泛应用仍然具有挑战性，因为它们在负极处有枝晶生长、高界面电阻和低阴极负载。在此，提出了一种双转换反应策略，以构建具有混合离子/电子导电 （MIEC） 结构域的紧凑多异质结构界面。获得的 LiF/Cu-Mo MIEC 层可以通过调节带电物质在非均相界面处的扩散和迁移来抑制锂枝晶生长并降低界面阻力。此外，为了解决阴极/石榴石界面接触阻抗高和体阴极导通不足的问题，开发了一种离子线的热熔渗透键合工艺，使全电池能够在不添加任何离子液体/电解质润湿剂的情况下正常工作。它能够构建具有连续锂离子传输通道并与石榴石电解质紧密接触的高负载阴极。因此，Li 对称电池表现出超过 10 000 小时的稳定循环，在 0.2 mA ^cm-2 处没有短路，具有仅 ∼10 mV 的低过电位和接近 2.5 A h ^cm-2 的超高累积容量。全固态转换反应电池具有高达 6 mg ^cm-2 的 FeF₃ 阴极高质量负载，在 0.3C 下循环 300 次后达到 300 mA h ^g-1 的高比容量。即使在 712 mA ^g-1 的超高电流密度下，可逆容量仍然超过 250 mA h ^g-1。 本研究证明了阳极和阴极侧的双重氟化作用，以开发基于转换阴极系统的高容量 AS-LMB。