A Graphene-like Oxygenated Carbon Nitride Material for Improved Cycle-Life Lithium/Sulfur Batteries
A Graphene-like Oxygenated Carbon Nitride Material for Improved Cycle-Life Lithium/Sulfur Batteries
复制标题
用于提高锂/硫电池循环寿命的类石墨烯氧化碳氮化物材料
DOI：
10.1021/acs.nanolett.5b01919
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发表时间：
2015-08-01
期刊：
影响因子：
10.8
通讯作者：
Zhang, Yuegang
中科院分区：
文献类型：
--
作者：
Liu, Jinghai;Li, Wanfei;Zhang, Yuegang
为了提高Li/S电池的性能，迫切需要新型硫（5）锚定材料和相应的抑制容量衰减的机制。在这里，我们设计并合成了石墨烯状含氧氮化碳（OCN）主体材料，其包含数十微米尺度的二维（2D）波纹片，微孔和氧杂原子。氮含量可高达20.49wt%。为实现低成本、规模化生产有机碳氮，提出了一种可持续发展的一步自支撑固相热解（OSSP）方法。固体来源中的尿素不仅提供自支撑气氛，而且还产生石墨碳氮化物（g-C3 N4），其用作2D层状模板。在C/20倍率下，S/OCN阴极的比容量可达1407.6mA·h·g（-1），S利用率为84%，在高电流密度下的长期循环中，可逆容量保持较高。在大尺寸OCN片上增加的微孔、石墨态N、醚和羧基0有利于S的利用和多硫化物的捕集。
Novel sulfur (5) anchoring materials and the corresponding mechanisms for suppressing capacity fading are urgently needed to advance the performance of Li/S batteries. Here, we designed and synthesized a graphene-like oxygenated carbon nitride (OCN) host material that contains tens of micrometer scaled two-dimensional (2D) rippled sheets, micromesopores, and oxygen heteroatoms. N content can reach as high as 20.49 wt %. A sustainable approach of one-step self-supporting solid-state pyrolysis (OSSP) was developed for the low-cost and large-scale production of OCN. The urea in solid sources not only provides self-supporting atmospheres but also produces graphitic carbon nitride (g-C3N4) working as 2D layered templates. The S/OCN cathode can deliver a high specific capacity of 1407.6 mA h g(-1) at C/20 rate with 84% S utilization and retain improved reversible capacity during long-term cycles at high current density. The increasing micropores, graphitic N, ether, and carboxylic 0 at the large sized OCN sheet favor S utilization and trapping for polysulfides.