锂离子电池用水性聚氨酯粘结剂的制备与性能研究

Preparation and properties of waterborne polyurethane binders for Lithium-ion battery

摘要:

以异佛尔酮二异氰酸酯（IPDI）、聚氧化丙烯二醇(N220)、聚己二酸新戊二醇酯二醇(PNA)、聚己二酸-1,4-丁二醇酯二醇(PBA)为主要原料，制备了三种水性聚氨酯(WPU)粘结剂。采用红外光谱(IR)、差示扫描量热测试(DSC)和热重分析(TG)对三种水性聚氨酯膜进行了结构表征并测试了它们的力学性能和溶胀性能。通过循环、倍率等测试研究了以这三种水性聚氨酯为粘结剂的锂电池的电化学性能并与以PVDF为粘结剂的电池进行比较。结果表明，以N220为软段的水性聚氨酯胶膜的拉伸强度为11MPa，玻璃化转变温度为-52℃，初始分解温度为273.6℃符合电池粘结剂的要求，并且以其作为粘结剂的电池在200次循环后，容量保持率可达到97.8%要明显高于其他三组。

Abstract:

Isophorone diisocyanate (IPDI), polyoxypropylene diol (N220), polyhexane adipate diol (PNA), polyadipate-1,4-butanediol diol (PBA) as the main raw material, three waterborne polyurethane (WPU) binders were prepared. Three aqueous polyurethane films were characterized by infrared spectroscopy (IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TG). Their mechanical properties and swelling properties were tested. The electrochemical performance of lithium batteries using these three aqueous polyurethanes as binders was investigated by cycles, magnifications, etc. and compared with batteries using PVDF as a binder. The results show that the tensile strength of waterborne polyurethane film with N220 as soft segment is 11 MPa, the glass transition temperature is -52 ?C, the initial decomposition temperature is 273.6 ?C, which meets the requirements of battery binder, and it is used as a binder. After 200 cycles, the capacity retention rate can reach 97.8%, which is significantly higher than the other three groups.