Hefei National Research Center 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, 230026, P. R. China.
Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang, 550018, P. R. China.
Small. 2022 Jul;18(30):e2203288. doi: 10.1002/smll.202203288. Epub 2022 Jul 3.
Carbon materials, as promising anode candidates for K storage due to their low cost, abundant sources, and high physicochemical stability, however, encounter limited specific capacity and unfavorable cycling stability that seriously hinder their practical applications. Herein, a feasible strategy to tailor and stabilize the nitrogen species in unique P/N co-doped disk-like carbon through the Sn incorporation (P/N -CD) is presented, which can largely enhance the specific capacity and cycling capability for K storage. Specifically, it delivers a high specific capacity of 439.3 mAh g at 0.1 A g and ultra-stable cycling capability with a capacity retention of 93.5% at 5000 mA g over 5000 cycles for K storage. The underlying mechanism for the superior K storage performance is investigated by systematical experimental data combined with theoretical simulation results, which can be derived from the increased edge-nitrogen species, improved content and stability of P/N heteroatoms, and enhanced ionic/electronic kinetics. After coupling P/N -CD anode with activated carbon cathode, the KIHCs can deliver a high energy density of 171.7 Wh kg at 106.8 W kg , a superior power density (14027.0 W kg with 31.2 Wh kg retained), and ultra-stable lifespan (89.7% retention after 30 K cycles with cycled at 2 A g ).
碳材料作为有前途的钾存储用阳极候选材料，由于其低成本、丰富的来源和高物理化学稳定性，但存在有限的比容量和不利的循环稳定性，严重阻碍了其实际应用。在此，提出了一种通过引入锡来调整和稳定独特的 P/N 共掺杂盘状碳中氮物种的可行策略（P/N-CD），这可以极大地提高钾存储的比容量和循环性能。具体而言，它在 0.1 A g 时提供了 439.3 mAh g 的高比容量，在 5000 mA g 下经过 5000 次循环后，容量保持率为 93.5%，具有超稳定的循环能力。通过系统的实验数据和理论模拟结果研究了其优越的钾存储性能的机制，可以得出增加边缘氮物种、提高 P/N 杂原子的含量和稳定性以及增强离子/电子动力学的结论。将 P/N-CD 阳极与活性炭阴极结合后，KIHCs 可以在 106.8 W kg 的高功率密度（14027.0 W kg 时保留 31.2 Wh kg）下提供 171.7 Wh kg 的高能量密度，具有超稳定的寿命（以 2 A g 循环 30 K 次后保留 89.7%）。
