Ma Jianfeng, Shi Xin, Wang Zhihui, Zhou Lijun, Liu Xinge, Lu Xihong, Jiang Zehui
Key Lab of Bamboo and Rattan Science & Technology, International Center for Bamboo and Rattan, Beijing, 100102, P. R. China.
MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry, The Key Lab of Low-carbon Chem & Energy Conservation of Guangdong Province, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, P. R. China.
Adv Mater. 2024 Nov;36(44):e2406429. doi: 10.1002/adma.202406429. Epub 2024 Sep 10.
Aqueous zinc ion batteries have gained attention as viable energy storage systems, yet the occurrence of detrimental side reactions and Zn dendrite formation undermines the efficiency of Zn anodes. Controlling water activity have proven to be an effective strategy in mitigating these challenges. However, strategies such as electrolyte design and electrode protection layer show weakness to varying degrees. Here, a new oxygen-functionalized biomass bamboo membrane separator (denoted as BM) is proposed to restrain the activity of water molecules. This BM separator features a unique, multi-tiered 2D interlayer that facilitates rapid ion diffusion. Additionally, the oxygen functional groups of the BM separator can form hydrogen bonds with water molecules, effectively transforming water molecules from a free state to a bound state. Consequently, the Zn/Zn asymmetric coin cell using BM can work at the ultrahigh rate and capacity of 30 mA cm and 30 mAh cm for more than 80 h while its counterparts using glass fiber can barely work. Moreover, full cells using BM separator exhibited a capacity retention of 89.7% after 1000 cycles at 10 A g. This study reveals the important influence of water-limited activity on Zn anode protection and provides an avenue for the design of novel separator.
水系锌离子电池作为一种可行的储能系统受到了关注，然而有害副反应的发生和锌枝晶的形成削弱了锌负极的效率。事实证明，控制水活性是缓解这些挑战的有效策略。然而，诸如电解质设计和电极保护层等策略在不同程度上存在弱点。在此，提出了一种新型的氧官能化生物质竹膜隔膜（称为BM）来抑制水分子的活性。这种BM隔膜具有独特的多层二维夹层结构，有利于离子快速扩散。此外，BM隔膜的氧官能团可与水分子形成氢键，有效地将水分子从自由状态转变为束缚状态。因此，使用BM的锌/锌不对称硬币电池能够以30 mA cm²的超高电流密度和30 mAh cm²的容量工作超过80小时，而使用玻璃纤维隔膜的同类电池几乎无法工作。此外，使用BM隔膜的全电池在10 A g⁻¹的电流密度下循环1000次后容量保持率为89.7%。这项研究揭示了水活性受限对锌负极保护的重要影响，并为新型隔膜的设计提供了一条途径。
