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通过可再生生物质制备的生物炭具有成本低、环保和资源可再生的优势。本研究以分布广泛的稻谷壳、芒草、杉木和柚子皮等生物质为原料,制备了4种不同类型生物炭,然后研究了其作为锂-硫电池硫/碳正极的载体的性能。研究表明由稻谷壳制备的硫/生物炭正极材料表现出最高的比容量和最优的循环稳定性。为了进一步改善其电性能,以SiO_2溶胶为模板制备了具有高孔隙率的稻谷壳生物炭,其多孔结构可有效抑制多硫化物的溶解。由此得到的硫/生物炭(硫含量为60%(w,质量分数))材料中的硫以无定型态均匀地分散在碳载体中。该材料表现出更优异的电化学性能:在0.2C(1C=1675 m A?g~(-1))倍率下,首周放电容量为1534.1 mAh?g~(-1),循环100周后仍可保持在783.7 mAh?g~(-1);倍率性能测试中,在2.0C倍率下,材料的可逆容量为485.3 mAh?g~(-1)。
Biochar prepared by renewable biomass has the advantage of low cost, environmental friendliness and renewable resources. In this study, four different types of biochar were prepared from widely distributed biomass such as rice husks, miscanthus, Chinese fir and grapefruit peel, and then their performance as carriers for lithium-sulfur batteries sulfur / carbon positive electrode was studied. Studies have shown that sulfur / biochar cathode materials prepared from rice hulls exhibit the highest specific capacity and the best cycling stability. In order to further improve its electrical properties, a porous SiO 2 sol was used as a template to prepare rice husk biochar with high porosity, whose porous structure can effectively inhibit polysulfide dissolution. The resulting sulfur / biochar (sulfur content of 60% (w, mass fraction)) sulfur in the material uniformly dispersed amorphous state in the carbon carrier. The material showed better electrochemical performance. The discharge capacity was 1534.1 mAh? G -1 at 0.2C (1 C = 1675 m A? G -1) magnification for 100 weeks It can still maintain at 783.7 mAh? G ~ (-1); in the rate performance test, the reversible capacity of the material is 485.3 mAh? G ~ (-1) at 2.0C rate.