Zhou Xiaoya, Huang Xin, He Shufan, Lu Yezi, Shen Xiao, Tang Shaochun
Key National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, People's Republic of China.
School of Science, Minzu University of China, Beijing 100081, People's Republic of China.
Inorg Chem. 2024 Aug 12;63(32):15081-15089. doi: 10.1021/acs.inorgchem.4c02052. Epub 2024 Aug 1.
Transition metal selenides, boasting remarkable specific capacity, have emerged as a promising electrode material. However, the substantial volume fluctuations during sodium ion insertion and extraction result in inadequate cyclic stability and rate performance, impeding their practical utility. Here, we synthesized N-doped carbon three-dimensional (3D) interconnected networks encapsulating (NiCo)Se nanoparticles, denoted as ((NiCo)Se/N-C), exhibiting a bead-like structure and carbon confinement through electrospinning and subsequent thermal treatment. The N-doped carbon 3D interconnected networks possess high porosity and ample volume buffering capacity, enhance conductivity, shorten ion diffusion paths, and mitigate mechanical stress induced by volume changes during cycling. The uniformly distributed (NiCo)Se nanoparticles, featuring a stable structure, demonstrate rapid electrochemical kinetics and numerous available active sites. The distinctive structure and composition of the optimized (NiCo)Se/N-C material showcase a high specific capacity (656.2 mAh g at 0.1 A g) and an outstanding rate capability. A kinetic analysis confirms that (NiCo)Se/N-C stimulates the pseudocapacitive Na storage mechanism with capacitance contributing up to 89.2% of the total capacity. This unique structure design and doping approach provide new insights into the design of electrode materials for high-performance batteries.
过渡金属硒化物具有卓越的比容量，已成为一种很有前景的电极材料。然而，在钠离子嵌入和脱出过程中大量的体积波动导致循环稳定性和倍率性能不足，阻碍了它们的实际应用。在此，我们通过静电纺丝及后续热处理合成了包裹着（NiCo）Se纳米颗粒的氮掺杂碳三维（3D）互连网络，记为（（NiCo）Se/N-C），其呈现出珠状结构且具有碳限制作用。氮掺杂碳3D互连网络具有高孔隙率和充足的体积缓冲能力，提高了导电性，缩短了离子扩散路径，并减轻了循环过程中体积变化引起的机械应力。均匀分布的（NiCo）Se纳米颗粒具有稳定的结构，展现出快速的电化学动力学和众多可用的活性位点。优化后的（NiCo）Se/N-C材料独特的结构和组成表现出高比容量（在0.1 A g下为656.2 mAh g）和出色的倍率性能。动力学分析证实，（NiCo）Se/N-C激发了赝电容钠存储机制，其电容贡献高达总容量的89.2%。这种独特的结构设计和掺杂方法为高性能电池电极材料的设计提供了新的思路。
