Zheng Ziyan, Guo Shaojie, Yan Mengyu, Luo Yanzhu, Cao Feifei
College of Chemistry, Huazhong Agricultural University, 430070, Wuhan, P. R. China.
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, P. R. China.
Adv Mater. 2023 Nov;35(47):e2304667. doi: 10.1002/adma.202304667. Epub 2023 Oct 16.
Aqueous zinc-ion batteries (AZIBs) offer promising prospects for large-scale energy storage due to their inherent abundance and safety features. However, the growth of zinc dendrites remains a primary obstacle to the practical industrialization of AZIBs, especially under harsh conditions of high current densities and elevated temperatures. To address this issue, a Janus separator with an exceptionally ultrathin thickness of 29 µm is developed. This Janus separator features the bacterial cellulose (BC) layer on one side and Ag nanowires/bacterial cellulose (AgNWs/BC) layer on the other side. High zincophilic property and excellent electric/thermal conductivity of AgNWs make them ideal for serving as an ion pump to accelerate Zn transport in the electrolyte, resulting in greatly improved Zn conductivity, deposition of homogeneous Zn nuclei, and dendrite-free Zn. Consequently, the Zn||Zn symmetrical cells with the Janus separator exhibit a stable cycle life of over 1000 h under 80 mA cm and are sustained for over 600 h at 10 mA cm under 50 °C. Further, the Janus separator enables excellent cycling stability in AZIBs, aqueous zinc-ion capacitors (AZICs), and scaled-up flexible soft-packaged batteries. This study demonstrates the potential of functional separators in promoting the application of aqueous zinc batteries, particularly under harsh conditions.
水系锌离子电池（AZIBs）因其固有的丰富性和安全特性，在大规模储能方面具有广阔的前景。然而，锌枝晶的生长仍然是水系锌离子电池实际工业化的主要障碍，特别是在高电流密度和高温等苛刻条件下。为了解决这个问题，开发了一种厚度仅为29微米的超薄Janus隔膜。这种Janus隔膜一侧是细菌纤维素（BC）层，另一侧是银纳米线/细菌纤维素（AgNWs/BC）层。银纳米线具有高亲锌性和优异的电/热导率，使其成为加速锌在电解质中传输的理想离子泵，从而大大提高了锌的导电性，实现了均匀的锌核沉积，并抑制了锌枝晶的生长。因此，采用Janus隔膜的锌||锌对称电池在80 mA cm下具有超过1000小时的稳定循环寿命，在50°C下10 mA cm时可持续超过600小时。此外，Janus隔膜在水系锌离子电池、水系锌离子电容器（AZICs）和放大的柔性软包电池中都具有出色的循环稳定性。这项研究证明了功能隔膜在促进水系锌电池应用方面的潜力，特别是在苛刻条件下。
