Chloride electrolyte enabled practical zinc metal battery with a near-unity Coulombic efficiency
Chloride electrolyte enabled practical zinc metal battery with a near-unity Coulombic efficiency
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DOI：
10.1038/s41893-023-01092-x
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发表时间：
2023-03-23
影响因子：
27.6
通讯作者：
Ji, Xiulei
中科院分区：
文献类型：
--
作者：
Jiang, Heng;Tang, Longteng;Ji, Xiulei
可充电锌水溶液电池在固定存储应用中找到了自己的位置，其中安全性，成本，可扩展性和碳足迹最为重要。然而，利用这种可逆的双电子氧化还原化学过程受到主要技术问题的困扰，特别是锌表面的析氢反应（HER），其影响在典型的测量条件下通常无法显示。在这里，我们报告了一种浓缩的电解液设计，消除了这种寄生反应，并使库仑效率（CE）为99.95%的锌电镀/剥离在0.2 mA cm（-2）的低电流密度测量。在浓ZnCl 2电解质中加入额外的氯化物盐和碳酸二甲酯，具有独特化学环境的混合电解质具有低Hammett酸度的特征，并有助于原位形成双层固体电解质界面，保护锌阳极免受HER和枝晶生长的影响。受益于接近统一的CE，具有VOPO 4中心点2 H（2）O阴极的袋式电池可维持500次深度循环而不膨胀或泄漏，并在实际条件下提供100 Wh kg（-1）的能量密度。我们的工作代表了加速锌电池作为具有更高可持续性的储能系统的市场采用的关键一步。可充电水性锌电池被誉为可持续能源技术，但仍面临技术挑战。这里的混合电解质消除了析氢反应，这是最棘手的问题，即使在恶劣的条件下也能实现令人印象深刻的电池性能。
Rechargeable aqueous zinc batteries are finding their niche in stationary storage applications where safety, cost, scalability and carbon footprint matter most. However, harnessing this reversible two-electron redox chemistry is plagued by major technical issues, notably hydrogen evolution reaction (HER) at the zinc surface, whose impacts are often not revealed under typical measurement conditions. Here we report a concentrated electrolyte design that eliminates this parasitic reaction and enables a Coulombic efficiency (CE) of 99.95% for Zn plating/stripping measured at a low current density of 0.2 mA cm(-2). With extra chloride salts and dimethyl carbonate in concentrated ZnCl2 electrolyte, the hybrid electrolyte with a unique chemical environment features low Hammett acidity and facilitates the in situ formation of a dual-layered solid electrolyte interphase, protecting zinc anodes from HER and dendrite growth. Benefiting from the near-unity CE, the pouch cell with a VOPO4 center dot 2H(2)O cathode sustains 500 deep cycles without swelling or leaking and delivers an energy density of 100 Wh kg(-1) under practical conditions. Our work represents a critical step forward in accelerating the market adoption of zinc batteries as an energy storage system with higher sustainability.Rechargeable aqueous zinc batteries are heralded as a sustainable energy technology but still face technical challenges. The hybrid electrolyte here eliminates hydrogen evolution reaction, the most thorny issue, and allows for impressive battery performance even under harsh conditions.