Tian Xing, Shi Hailing, Wang Linfeng, Shao Lupeng, Tan Liwen
State Key Laboratory of Biomaterials and Green Papermaking, Qilu University of Technology, Jinan 250306, China.
State Key Laboratory of Bio-Fibers and Eco-Textiles, School of Material Science and Engineering, Institute of Marine Bio-Based Materials, Qingdao University, Qingdao 266071, China.
Molecules. 2024 Nov 11;29(22):5311. doi: 10.3390/molecules29225311.
As one of the most critical components in lithium-ion batteries (LIBs), commercial polyolefin separators suffer from drawbacks such as poor thermal stability and the inability to inhibit the growth of dendrites, which seriously threaten the safety of LIBs. In this study, we prepared calcium alginate fiber/boron nitride-compliant separators (CA@BN) through paper-making technology and the surface coating method using calcium alginate fiber and boron nitride. The CA@BN had favorable electrolyte wettability, flame retardancy, and thermal dimensional stability of the biomass fiber separator. Meanwhile, the boron nitride coating provided excellent thermal conductivity and mechanical strength for the composite separator, which inhibited the growth of lithium dendrites and enabled lithium-ion symmetric batteries to achieve more than 1000 stable and long cycles at a current density of 0.5 mA cm. The interwoven fiber mesh formed by the boron nitride coating and the calcium alginate provided multiple pathways for ion migration, which enhanced the storage capacity of the electrolyte, improved the interfacial compatibility between the separator and the electrode, widened the window of electrochemical stability, and enhanced ionic migration. This eco-friendly bio-based separator paves a new insight for the design of heat-resistance separators as well as the safe running of LIBs.
作为锂离子电池（LIBs）中最关键的组件之一，商用聚烯烃隔膜存在热稳定性差和无法抑制枝晶生长等缺点，这严重威胁着锂离子电池的安全性。在本研究中，我们通过造纸技术和表面涂覆法，使用海藻酸钙纤维和氮化硼制备了海藻酸钙纤维/氮化硼复合隔膜（CA@BN）。CA@BN具有良好的电解质润湿性、阻燃性以及生物质纤维隔膜的热尺寸稳定性。同时，氮化硼涂层为复合隔膜提供了优异的热导率和机械强度，抑制了锂枝晶的生长，使锂离子对称电池在0.5 mA cm的电流密度下能够实现1000多次稳定的长循环。由氮化硼涂层和海藻酸钙形成的交织纤维网为离子迁移提供了多条路径，增强了电解质的存储容量，改善了隔膜与电极之间的界面相容性，拓宽了电化学稳定性窗口，并增强了离子迁移。这种环保型生物基隔膜为耐热隔膜的设计以及锂离子电池的安全运行开辟了新的思路。
