纤维素微孔锂电隔膜的制备及性能研究

为了改善锂电隔膜的亲液性和耐高温性，以醋酸纤维素为成膜材料，利用相转化法制备了新型锂电隔膜，通过形貌和孔道结构表征、亲液性能和耐热性能测试对醋酸纤维素隔膜的基本性能进行研究，并将该隔膜装配成锂离子电池进行充放电性能测试. 结果表明，醋酸纤维素隔膜具有均匀的微孔结构，孔隙率达到65%，约为传统聚烯烃隔膜的1.5倍；纤维素材料的良好亲液性和高孔隙率结构改善了隔膜的吸液性能，其吸液率达到285%；该隔膜在150 ^oC、30 min的热处理条件下未发生明显的热收缩. 鉴于上述优点，相对于市售PE隔膜，醋酸纤维素隔膜所装配锂离子电池显示出更优的循环性能和倍率性能.

Preparation and Characterization of Cellulose Acetate-based Separator for Lithium-ion batteries

To improve the electrolyte wettability and thermal resistance of separators used for lithium-ion battery, a novel cellulose acetate (CA)-based separator is facilely prepared by non-solvent induced phase separation (NIPS) wet-process and investigated in lithium-ion batteries. Systematical investigations including morphological characterization, electrolyte wettability and thermal resistance testing were carried out. The results demonstrated that the CA-based separator exhibited well developed three-dimensional porous structures with porosity up to 65%, which is 1.5 times higher than that of PE separator. The CA separator also showed excellent electrolyte uptake (285%) and thermal stability at 150 ^oC for 30 min. Compared with the commercial PE separator, the CA separator exhibited better electrochemical performances, achieving superior discharge C-rate capability and cycling performance.