Zhou Hongyang, Gu Jin, Zhang Weiwei, Hu Chuanshuang, Lin Xiuyi
Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China.
Molecules. 2021 Sep 12;26(18):5539. doi: 10.3390/molecules26185539.
Cellulose nanofibrils (CNF) with high thermal stability and excellent electrolyte wettability attracted tremendous attention as a promising separator for the emerging sodium-ion batteries. The pore structure of the separator plays a vital role in electrochemical performance. CNF separators are assembled using the bottom-up approach in this study, and the pore structure is carefully controlled through film-forming techniques. The acid-treated separators prepared from the solvent exchange and freeze-drying demonstrated an optimal pore structure with a high electrolyte uptake rate (978.8%) and Na transference number (0.88). Consequently, the obtained separator showed a reversible specific capacity of 320 mAh/g and enhanced cycling performance at high rates compared to the commercial glass fiber separator (290 mAh/g). The results highlight that CNF separators with an optimized pore structure are advisable for sodium-ion batteries.
具有高热稳定性和优异电解质润湿性的纤维素纳米纤维（CNF）作为新兴钠离子电池的一种有前景的隔膜引起了极大关注。隔膜的孔结构对电化学性能起着至关重要的作用。本研究采用自下而上的方法组装CNF隔膜，并通过成膜技术仔细控制孔结构。由溶剂交换和冷冻干燥制备的酸处理隔膜表现出最佳的孔结构，具有高电解质吸收率（978.8%）和钠迁移数（0.88）。因此，与商用玻璃纤维隔膜（290 mAh/g）相比，所得隔膜显示出320 mAh/g的可逆比容量，并在高倍率下具有增强的循环性能。结果表明，具有优化孔结构的CNF隔膜适用于钠离子电池。
