College of Materials Science and Engineering, Zhejiang University of Technology , Hangzhou 310014, China.
College of Materials Science and Engineering, China Jiliang University , Hangzhou 310018, China.
ACS Appl Mater Interfaces. 2017 Jul 19;9(28):23782-23791. doi: 10.1021/acsami.7b05798. Epub 2017 Jul 7.
Lithium-sulfur (Li-S) battery is one of the most attractive candidates for the next-generation energy storage system. However, the intrinsic insulating nature of sulfur and the notorious polysulfide shuttle are the major obstacles, which hinder the commercial application of Li-S battery. Confining sulfur into conductive porous carbon matrices with designed polarized surfaces is regarded as a promising and effective strategy to overcome above issues. Herein, we propose to use microalgaes (Schizochytrium sp.) as low-cost, renewable carbon/nitrogen precursors and biological templates to synthesize N-doped porous carbon microspheres (NPCMs). These rational designed NPCMs can not only render the sulfur-loaded NPCMs (NPCSMs) composites with high electronic conductivity and sulfur content, but also greatly suppress the diffusion of polysulfides by strongly physical and chemical adsorptions. As a result, NPCSMs cathode demonstrates a superior reversible capacity (1030.7 mA h g) and remarkable capacity retention (91%) at 0.1 A g after 100 cycles. Even at an extremely high current density of 5 A g, NPCSMs still can deliver a satisfactory discharge capacity of 692.3 mAh g. This work reveals a sustainable and effective biosynthetic strategy to fabricate N-doped porous carbon matrices for high performance sulfur cathode in Li-S battery, as well as offers a fascinating possibility to rationally design and synthesize novel carbon-based composites.
锂硫（Li-S）电池是下一代储能系统最具吸引力的候选者之一。然而，硫的固有绝缘性质和臭名昭著的多硫化物穿梭现象是主要障碍，阻碍了 Li-S 电池的商业应用。将硫限制在具有设计的极化表面的导电多孔碳基质中被认为是克服上述问题的一种有前途和有效的策略。在此，我们提出使用微藻类（裂殖壶菌）作为低成本、可再生的碳/氮前体和生物模板来合成氮掺杂多孔碳微球（NPCM）。这些合理设计的 NPCM 不仅可以使负载硫的 NPCM（NPCSM）复合材料具有高电子导电性和硫含量，而且还可以通过强物理和化学吸附大大抑制多硫化物的扩散。结果，NPCSM 阴极在 100 次循环后在 0.1 A g 时表现出优异的可逆容量（1030.7 mA h g）和显著的容量保持率（91%）。即使在极高的电流密度 5 A g 下，NPCSM 仍能提供令人满意的放电容量 692.3 mAh g。这项工作揭示了一种可持续且有效的生物合成策略，用于制造用于 Li-S 电池的高性能硫阴极的氮掺杂多孔碳基质，以及为合理设计和合成新型碳基复合材料提供了引人入胜的可能性。
