Li Senlin, Hu Sanlue, Li Hongfei, Han Cuiping
Faculty of Materials Science and Energy Engineering/Institute of Technology for Carbon Neutrality, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
School of System Design and Intelligent Manufacturing, Southern University of Science and Technology, Shenzhen, 518055, China.
Angew Chem Int Ed Engl. 2024 Mar 11;63(11):e202318885. doi: 10.1002/anie.202318885. Epub 2024 Feb 2.
Alkaline metal-air batteries are advantageous in high voltage, low cost, and high safety. However, metal anodes are heavily eroded in strong alkaline electrolytes, causing serious side reactions including dendrite growth, passivation, and hydrogen evolution. To address this limitation, we successfully synthesized an organic N-heterocycle compound (NHCC) to serve as an alternative anode. This compound not only exhibits remarkable stability but also possesses a low redox potential (-1.04 V vs. Hg/HgO) in alkaline environments. To effectively complement the low redox potential of the NHCC anode, we designed a dual-salt highly concentrated electrolyte (4.0 M KOH+10.0 M KCF SO ). This electrolyte expands the electrochemical stability window to 2.3 V through the robust interaction between the O atom in H O molecule with the K of KCF SO (H-O⋅⋅⋅KCF SO ). We further demonstrated the K uptaken/extraction storage mechanism of NHCC anodes. Consequently, the alkaline aqueous NHCC anode-air batteries delivers a high battery voltage of 1.6 V, high-rate performance (101.9 mAh g at 100 A g ) and long cycle ability (30,000 cycles). Our work offers a molecular engineering strategy for superior organic anode materials and develops a novel double superconcentrated conductive salt electrolyte for the construction of high-rate, long-cycle alkaline aqueous organic anode-air batteries.
碱金属空气电池在高电压、低成本和高安全性方面具有优势。然而，金属阳极在强碱性电解质中会被严重腐蚀，引发包括枝晶生长、钝化和析氢等严重的副反应。为解决这一限制，我们成功合成了一种有机氮杂环化合物（NHCC）作为替代阳极。该化合物不仅表现出卓越的稳定性，而且在碱性环境中具有较低的氧化还原电位（相对于Hg/HgO为-1.04 V）。为有效弥补NHCC阳极较低的氧化还原电位，我们设计了一种双盐高浓度电解质（4.0 M KOH + 10.0 M KCF₃SO₃）。这种电解质通过水分子中的O原子与KCF₃SO₃中的K之间的强相互作用（H-O⋅⋅⋅KCF₃SO₃）将电化学稳定窗口扩展至2.3 V。我们进一步证明了NHCC阳极的K⁺摄取/提取存储机制。因此，碱性水系NHCC阳极空气电池具有1.6 V的高电池电压、高倍率性能（100 A g⁻¹时为101.9 mAh g⁻¹）和长循环能力（30,000次循环）。我们的工作为制备优异的有机阳极材料提供了一种分子工程策略，并开发了一种新型的双超浓导电盐电解质，用于构建高倍率、长循环的碱性水系有机阳极空气电池。
