Wang Ning, Liu Qinglei, Sun Boya, Gu Jiajun, Yu Boxuan, Zhang Wang, Zhang Di
State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P.R. China.
CRRC Industrial Institute Co., Ltd, Beijing, China.
Sci Rep. 2018 Jul 2;8(1):9934. doi: 10.1038/s41598-018-28310-3.
Hard carbon attracts wide attentions as the anode for high-energy rechargeable batteries due to its low cost and high theoretical capacities. However, the intrinsically disordered microstructure gives it poor electrical conductivity and unsatisfactory rate performance. Here we report a facile synthesis of N-doped graphitized hard carbon via a simple carbonization and activation of a urea-soaked self-crosslinked Co-alginate for the high-performance anode of lithium/sodium-ion batteries. Owing to the catalytic graphitization of Co and the introduction of nitrogen-functional groups, the hard carbon shows structural merits of ordered expanded graphitic layers, hierarchical porous channels, and large surface area. Applying in the anode of lithium/sodium-ion batteries, the large surface area and the existence of nitrogen functional groups can improve the specific capacity by surface adsorption and faradic reaction, while the hierarchical porous channels and expanded graphitic layers can provide facilitate pathways for electrolyte and improve the rate performance. In this way, our hard carbon provides its feasibility to serve as an advanced anode material for high-energy rechargeable lithium/sodium-ion batteries.
硬碳因其低成本和高理论容量而作为高能可充电电池的负极受到广泛关注。然而，其固有的无序微观结构使其导电性差且倍率性能不理想。在此，我们报道了一种通过对尿素浸渍的自交联钴藻酸盐进行简单碳化和活化来简便合成氮掺杂石墨化硬碳的方法，用于锂/钠离子电池的高性能负极。由于钴的催化石墨化作用以及氮官能团的引入，该硬碳具有有序膨胀石墨层、分级多孔通道和大表面积等结构优点。应用于锂/钠离子电池负极时，大表面积和氮官能团的存在可通过表面吸附和法拉第反应提高比容量，而分级多孔通道和膨胀石墨层可为电解质提供便利通道并改善倍率性能。通过这种方式，我们的硬碳为作为高能可充电锂/钠离子电池的先进负极材料提供了可行性。
