Li-CO₂ batteries (LCOBs) are considered to be an important strategy toward efficient carbon sequestration and energy storage. However, most typical discharge products (Li₂CO₃ and C) are insoluble and chemically stable, and require a high charge overpotential (≈3.5–4.5 V) to be decomposed. Herein, a novel aqueous LCOB with formic acid (HCOOH) as the discharge product is proposed. The soluble HCOOH can be directly utilized in the charge process without any further purification or compression, realizing a very facile electrochemical cycle. Nanoporous Pd films with a high electrochemical surface area exhibit a high bifunctional performance toward both CO₂ reduction and formic acid oxidation. Accordingly, the assembled LCOB achieves a high working potential plateau of 2.61 V whereas the charge potential is significantly lowered to 2.87 V, delivering the highest energy efficiency of 91%. The present work demonstrates a brand-new aqueous LCOB with HCOOH as the discharge product for utilizing CO₂ as power source.

中文翻译：

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具有低充电过电位和高工作电压的甲酸锂基锂电池

Li-CO ₂电池（LCOB）被认为是实现高效碳封存和能量存储的重要策略。然而，大多数典型的放电产物（Li ₂ CO ₃和 C）是不溶性和化学稳定的，需要高电荷过电位（≈3.5-4.5 V）才能分解。在此，提出了一种以甲酸 (HCOOH) 作为放电产物的新型水性 LCOB。可溶性 HCOOH 可直接用于充电过程，无需任何进一步纯化或压缩，实现非常容易的电化学循环。具有高电化学表面积的纳米多孔 Pd 薄膜对 CO _{2 和}还原和甲酸氧化。因此，组装后的 LCOB 实现了 2.61 V 的高工作电位平台，而充电电位显着降低至 2.87 V，提供了 91% 的最高能效。目前的工作展示了一种全新的水性 LCOB，以 HCOOH 作为放电产物，利用 CO ₂作为动力源。