【摘要】 通过γ射线辐照交联异型聚丙烯腈(PAN)纤维解决了低分子量聚丙烯腈半碳化中的熔融坍塌问题,提高了PAN的半碳化稳定性;采用傅里叶变换红外光谱、元素分析及核磁共振波谱确定了辐照交联机理.同时,根据辐照产生的不同交联度与PAN硫化后载硫量的变化关系,探讨了硫化聚丙烯腈(SPAN)锂硫电池正极材料的储硫机理.利用拉曼光谱及X射线光电子能谱等分析手段表征了SPAN中硫原子的反应位置,说明PAN主链上的亚甲基所在的碳为与硫化学结合的活性位点,为探究SPAN结构提供了新的依据.交联度升高对硫化后所形成的SPAN正极材料的电化学稳定性起促进作用,容量保持率可提升至98%.更多还原

【Abstract】 By the method of γ-ray irradiation cross-linking heteromorphic polyacrylonitrile(PAN)fibers,the problem of melt collapse in the semi-carbonization of low-molecular-weight polyacrylonitrile was solved and the semicarbonization stability of PAN was impoved.The irradiation cross-linking mechanism was first determined by Fourier transform infrared spectra,elemental analysis and nuclear magnetic resonance spectra.At the same time,according to the relationship between the different degree of crosslinking produced by irradiation and the change of sulfur load after PAN vulcanization,the sulfur storage mechanism of vulcanized polyacrylonitrile(SPAN)for lithium-sulfur battery cathode material was discussed.Using Raman spectra,X-ray photoelectron spectra and other analytical methods,from the perspective of cross-linking,the reaction position of S in SPAN was demonstrated,and the tertiary carbon on the PAN main chain was the active site for chemical bonding with S.It provides a new basis for exploring the SPAN structure.The increase in the degree of cross-linking promotes the electrochemical stability of the SPAN cathode material formed after vulcanization,and the capacity retention rate can be increased to 98%.更多还原