State Key Laboratory of Fire Science , University of Science and Technology of China , Hefei , Anhui 230027 , P. R. China.
Civil and Infrastructure Engineering Discipline, School of Engineering , Royal Melbourne Institute of Technology University , Melbourne , Victoria 3001 , Australia.
ACS Appl Mater Interfaces. 2018 Sep 19;10(37):31441-31451. doi: 10.1021/acsami.8b11984. Epub 2018 Sep 7.
Na-ion batteries (NIBs) have attracted increasing attention given the fact that sodium is relatively more plentiful and affordable than lithium for sustainable and large-scale energy storage systems. However, the shortage of electrode materials with outstanding comprehensive properties has limited the practical implementations of NIBs. Among all the discovered anode materials, transition-metal sulfide has been proven as one of the most competitive and promising ones due to its excellent redox reversibility and relatively high theoretical capacity. In this study, double-morphology N-doped CoS/multichannel carbon nanofibers composites (CoS/MCNFs) are precisely designed, which overcome common issues such as the poor cycling life and inferior rate performance of CoS electrodes. The conductive 3D interconnected multichannel nanostructure of CoS/MCNFs provides efficient buffer zones for the release of mechanical stresses from Na ions intercalation/deintercalation. The synergy of the diverse structural features enables a robust frame and a rapid electrochemical reaction in CoS/MCNFs anode, resulting in an impressive long-term cycling life of 900 cycles with a capacity of 620 mAh g at 1 A g (86.4% theoretical capacity) and a surprisingly high-power output. The proposed design in this study provides a rational and novel thought for fabricating electrode materials.
钠离子电池（NIBs）由于钠比锂在可持续和大规模储能系统中更丰富、更经济实惠，因此受到了越来越多的关注。然而，具有出色综合性能的电极材料短缺限制了 NIBs 的实际应用。在所有已发现的阳极材料中，过渡金属硫化物因其优异的氧化还原可逆性和相对较高的理论容量而被证明是最具竞争力和前景的材料之一。在这项研究中，精确设计了双形态 N 掺杂 CoS/多通道碳纳米纤维复合材料（CoS/MCNFs），克服了 CoS 电极循环寿命差和倍率性能差等常见问题。CoS/MCNFs 的导电 3D 互连多通道纳米结构为钠离子插层/脱插层过程中机械应力的释放提供了有效的缓冲区。多种结构特征的协同作用使 CoS/MCNFs 阳极具有坚固的框架和快速的电化学反应，从而实现了 900 次循环的出色长期循环寿命，在 1 A g 时的容量为 620 mAh g（86.4%理论容量），且具有令人惊讶的高功率输出。本研究中的设计为制造电极材料提供了合理而新颖的思路。
