Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing, People's Republic of China.
Nano Lett. 2015 Mar 11;15(3):1796-802. doi: 10.1021/acs.nanolett.5b00112. Epub 2015 Feb 5.
Lithium sulfide (Li2S) is a promising cathode material for Li-S batteries with high capacity (theoretically 1166 mAh g(-1)) and can be paired with nonlithium-metal anodes to avoid potential safety issues. However, the cycle life of coarse Li2S particles suffers from poor electronic conductivity and polysulfide shuttling. Here, we develop a flexible slurryless nano-Li2S/reduced graphene oxide cathode paper (nano-Li2S/rGO paper) by simple drop-coating. The Li2S/rGO paper can be directly used as a free-standing and binder-free cathode without metal substrate, which leads to significant weight savings. It shows excellent rate capability (up to 7 C) and cycle life in coin cell tests due to the high electron conductivity, flexibility, and strong solvent absorbency of rGO paper. The Li2S particles that precipitate out of the solvent on rGO have diameters 25-50 nm, which is in contrast to the 3-5 μm coarse Li2S particles without rGO.
硫化锂（Li2S）是一种很有前途的锂硫电池正极材料，具有高容量（理论上可达 1166 mAh g(-1))，且可与非锂金属负极搭配，以避免潜在的安全问题。然而，粗 Li2S 颗粒的循环寿命受到较差的电子导电性和多硫化物穿梭的影响。在这里，我们通过简单的滴涂法制备了一种柔性无浆料纳米 Li2S/还原氧化石墨烯正极纸（nano-Li2S/rGO 纸）。Li2S/rGO 纸可直接用作独立的、无粘结剂的正极，无需金属基底，从而显著减轻了重量。由于 rGO 纸具有高电子导电性、柔韧性和强溶剂吸收性，因此在纽扣电池测试中表现出优异的倍率性能（高达 7 C）和循环寿命。在 rGO 上沉淀出的溶剂中的 Li2S 颗粒直径为 25-50nm，而没有 rGO 的粗 Li2S 颗粒直径为 3-5μm。
