Gao Jingyu, Wang Gongrui, Wang Wentao, Yu Lai, Peng Bo, El-Harairy Ahmed, Li Jie, Zhang Genqiang
Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China.
Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018, China.
ACS Nano. 2022 Apr 26;16(4):6255-6265. doi: 10.1021/acsnano.2c00140. Epub 2022 Mar 18.
Sodium and potassium ions energy storage systems with low cost and high energy/power densities have recently drawn increasing interest as promising candidates for grid-level applications, while the lack of suitable anode materials with fast ion diffusion kinetics highly hinders their development. Herein, we develop a nanoscale confined oxidation polymerization process followed by a conventional carbonization treatment to generate phosphorus and nitrogen dual-doped hollow carbon spheres (PNHCS), which can realize superior sodium and potassium ion storage performance. Importantly, the density functional theory calculation and combined characterizations, , Raman spectroscopy and X-ray photoelectron spectroscopy, decipher that the P/N doping can enhance the electronic transfer dynamics and ion adsorption capability, which are responsible for enhanced electrochemical performance. Inspiringly, the practicability of the PNHCS anode is demonstrated by assembling the potassium ion hybrid capacitors (KIHCs), where the prominent energy density is 178.80 Wh kg at a power density of 197.65 W kg, with excellent cycling stability, can be achieved. This work not only promotes the development of efficient anode material for sodium/potassium ion storage devices but also deciphers the embedded ion storage mechanism.
具有低成本和高能量/功率密度的钠钾离子储能系统最近作为电网级应用的有前途的候选者引起了越来越多的关注，而缺乏具有快速离子扩散动力学的合适负极材料严重阻碍了它们的发展。在此，我们开发了一种纳米级受限氧化聚合工艺，随后进行传统的碳化处理，以制备磷氮双掺杂空心碳球（PNHCS），其可实现优异的钠钾离子存储性能。重要的是，密度泛函理论计算以及拉曼光谱和X射线光电子能谱等联合表征表明，P/N掺杂可增强电子转移动力学和离子吸附能力，这是电化学性能增强的原因。令人鼓舞的是，通过组装钾离子混合电容器（KIHC）证明了PNHCS负极的实用性，在功率密度为197.65 W kg时，其突出的能量密度为178.80 Wh kg，可实现优异的循环稳定性。这项工作不仅促进了用于钠/钾离子存储装置的高效负极材料的发展，还阐明了嵌入的离子存储机制。
