锂离子电池硅碳负极用壳聚糖粘结剂的性能研究

Performance of Chitosan as the Binder for Si/C Anode of Li-ion Batteries

研究了壳聚糖(CS)粘结剂在锂离子电池硅碳负极中的性能。通过XRD、红外光谱和SEM表征粘结剂和电极的结构与形貌,测试了粘结剂的剥离强度,通过电化学性能和电极动力学比较了壳聚糖与聚偏氟乙烯(PVDF)作为粘结剂对硅碳复合材料电化学性能的影响。结果表明:CS粘结剂和PVDF粘结剂极片剥离强度分别为10.5和7.6 N/m,水溶性高分子CS粘结力更强;CS、PVDF作为硅碳负极粘结剂首次可逆比容量分别为572.4和568.3 m Ah/g,首次库伦效率分别为78.4%和79.5%,50次循环后容量保持率分别为72.3%和65.8%。与PVDF相比,CS更适合应用于锂离子电池硅碳负极材料中。

With Chitosan（ CS） as the binder for Si / C anode of lithium-ion batteries,X-ray diffractometry（ XRD）,Fourier transform infrared spectra（ FI-IR） and scanning electron microscopy（ SEM） were used to characterize the structure and morphology of the binder and electrodes,and peel strength of the binder was measured in the tests. The effect of chitosan as binder on the electrochemical performance of Si / C composite was investigated in comparison with poly（ vinylidene fluoride）（ PVDF） binder in terms of electrochemical performance and electrode kinetics. Results showed the peel strength of the CS and PVDF were respectively 10. 5 and 7. 6 N / m,composites using CS and PVDF separately as the binder had the initial reversible specific capacity of 572. 4 and 568. 3 m Ah / g,and the initial coulombic efficiency of 78. 4% and 79. 5%,respectively. Moreover,the capacity retention rates after 50 cycles reached 72. 3%and 65. 8%,respectively. Consequently,CS can be regarded as a better binder for Si / C anode than PVDF.