Aqueous dual‐ion batteries (DIBs) are promising for large‐scale energy storage due to low cost and inherent safety. However, DIBs are limited by low capacity and poor cycling of cathode materials and the challenge of electrolyte decomposition. In this study, a new cathode material of nitrogen‐doped microcrystalline graphene‐like carbon is investigated in a water‐in‐salt electrolyte of 30 m ZnCl₂, where this carbon cathode stores anions reversibly via both electrical double layer adsorption and ion insertion. The (de)insertion of anions in carbon lattice delivers a high‐potential plateau at 1.85 V versus Zn²⁺/Zn, contributing nearly 1/3 of the capacity of 134 mAh g⁻¹ and half of the stored energy. This study shows that both the unique carbon structure and concentrated ZnCl₂ electrolyte play critical roles in allowing anion storage in carbon cathode for this aqueous DIB.

中文翻译：

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水性锌双离子电池用高电势负离子插入碳阴极

双离子水电池（DIB）具有低成本和本质安全性，有望用于大规模储能。然而，DIB受到阴极材料的低容量和不良循环以及电解质分解的挑战的限制。在这项研究中，在30 m ZnCl ₂的盐包水电解质中研究了一种氮掺杂的微晶石墨烯状碳的新型阴极材料，该碳阴极通过双电层吸附和离子插入可逆地存储阴离子。相对于Zn ²⁺ / Zn，阴离子在碳晶格中的（去插入）在1.85 V时可提供高电势平台，贡献了134 mAh g ^-1容量的近1/3和一半的存储能量。这项研究表明，独特的碳结构和浓缩的ZnCl ₂电解质在允许阴离子在该水性DIB的碳阴极中存储方面都起着关键作用。