水性聚氨酯基锂离子电池粘结剂的制备与性能

Waterborne polyurethane based binder for lithium ion batteries

以聚氧化丙烯二醇、异佛尔酮二异氰酸酯、三羟甲基丙烷聚乙二醇为主要原料制备水性聚氨酯(WPU),再以水性聚氨酯为粘结剂与磷酸铁锂(LiFePO4)和导电炭黑(SP)混合,得到正极膜片,通过循环、倍率等测试,研究以水性聚氨酯为粘结剂与以聚偏氟乙烯为粘结剂所组装的电池的电化学性能。研究表明,以水性聚氨酯为粘结剂按质量比m(LiFePO4)∶m(WPU)∶m(SP)=90∶5∶5调浆制备的正极膜所组装锂离子电池电化学性能最优,在0. 2,1,2,3,5 C时,放电容量分别为162,131,105,90,69 m Ah/g,以0. 2 C倍率循环500次,容量保持率为78. 8%。

Waterborne polyurethane(WPU)based binder was synthesised by polyoxypropylene glycol,isophorone diisocyanate and trimethylolpropanepolyethyleneglycol.The cathodes for lithium ion batteries were prepared by mixing WPU,Licarbon black(SP).The electrochemical performances of the batteries assembled with waterborne polyurethane binder and polyvinylidene fluoride(PVDF)binder as a contrastive sample were also studied through the tests of rate and cycling performances of the batteries.The results indicate that the battery using the cathode with the mass ratio of m(Li)∶m(WPU)∶m(SP)=90∶5∶5 showed the best with the discharge capacity reaches at 0.2,1,2,3,5 C crate of 162,131,105,90,69 m Ah/g,respectively.In addition,the discharge capacity retention of the battery is 78.8% at 0.2 C after 500 cycles.