Lebherz Tim, Frey Martin, Hintennach Andreas, Buchmeiser Michael R
Institute of Polymer Chemistry, University of Stuttgart 70569 Stuttgart Germany
Daimler AG, RD/EBT, HPC G012-BB 71034 Böblingen Germany.
RSC Adv. 2019 Mar 4;9(13):7181-7188. doi: 10.1039/c8ra09976f. eCollection 2019 Mar 1.
Solvent-induced phase separation (SIPS) and thermally-induced phase separation (TIPS) derived poly(acrylonitrile) (PAN) based monoliths with different morphology and specific surface area were prepared and thermally converted into monolithic sulfur-poly(acrylonitrile) (SPAN) materials for use as active cathode materials in lithium-sulfur batteries. During thermal processing, the macroscopic monolithic structure fully prevailed while significant changes in porosity were observed. Both the monomer content in the precursor PAN-based monoliths and the tortuosity of the final monolithic SPAN materials correlate with the electrochemical performance of the SPAN-based cathodes. Overall, percolation issues predominate. In percolating SPAN-based cathode materials, the specific capacity of the SPAN-based cells increases with decreasing tortuosity. All monolithic SPAN materials provided highly reversible and cycle stable cathodes reaching reversible discharge capacities up to 1330 mA h g @ 0.25C, 900 mA h g @ 2C and 420 mA h g @ 8C.
制备了具有不同形态和比表面积的溶剂诱导相分离（SIPS）和热诱导相分离（TIPS）衍生的聚（丙烯腈）（PAN）基整体材料，并将其热转化为整体硫-聚（丙烯腈）（SPAN）材料，用作锂硫电池的活性阴极材料。在热处理过程中，宏观整体结构得以完全保留，同时观察到孔隙率有显著变化。基于PAN的前驱体整体材料中的单体含量和最终整体SPAN材料的曲折度均与基于SPAN的阴极的电化学性能相关。总体而言，渗流问题占主导。在渗流的基于SPAN的阴极材料中，基于SPAN的电池的比容量随曲折度的降低而增加。所有整体SPAN材料都提供了高度可逆且循环稳定的阴极，在0.25C、2C和8C下的可逆放电容量分别高达1330 mA h g、900 mA h g和420 mA h g。
