Wang Xiaoyu, Zheng Wenqiu, Zhao Hui, Li Junying, Chen Sheng, Xu Feng
State Key Laboratory of Efficient Production of Forest Resources, Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing, 100083, People's Republic of China.
Nanomicro Lett. 2025 Feb 19;17(1):153. doi: 10.1007/s40820-025-01650-2.
Separators in supercapacitors (SCs) frequently suffer from high resistance and the risk of short circuits due to inadequate electrolyte wettability, depressed mechanical properties, and insufficient thermal stability. Here, we develop a high-performance regenerated cellulose separator with nano-cracked structures for SCs via a binary solvent of superbase-derived ionic liquid and dimethylsulfoxide (DMSO). The unique nano-cracks with an average width of 7.45 nm arise from the acceleration of cellulose molecular reassembly by DMSO-regulated hydrogen bonding, which endows the separator with high porosity (70.2%) and excellent electrolyte retention (329%). The outstanding thermal stability (273 °C) and mechanical strength (70 MPa) enable the separator to maintain its structural integrity under high temperatures and external forces. With these benefits, the SC utilizing the cellulose separator enables a high specific capacitance of 93.6 F g at 1.0 A g and a remarkable capacitance retention of 99.5% after 10,000 cycles compared with the commercial NKK-MPF30AC and NKK-TF4030. The robust and high-wettability cellulose separator holds promise as a superior alternative to commercial separators for advanced SCs with enhanced performance and improved safety.
超级电容器（SCs）中的隔膜常常因电解质润湿性不足、机械性能不佳和热稳定性不足而面临高电阻和短路风险。在此，我们通过超强碱衍生离子液体和二甲基亚砜（DMSO）的二元溶剂，开发了一种用于SCs的具有纳米裂纹结构的高性能再生纤维素隔膜。平均宽度为7.45纳米的独特纳米裂纹源自DMSO调节的氢键加速纤维素分子重新组装，这赋予隔膜高孔隙率（70.2%）和出色的电解质保留率（329%）。出色的热稳定性（273°C）和机械强度（70MPa）使隔膜能够在高温和外力下保持其结构完整性。得益于这些优点，与商用NKK-MPF30AC和NKK-TF4030相比，使用纤维素隔膜的SCs在1.0A g时具有93.6F g的高比电容，并且在10000次循环后具有99.5%的显著电容保持率。这种坚固且高润湿性的纤维素隔膜有望成为商用隔膜的优质替代品，用于性能增强和安全性提高的先进SCs。
