Li Zhibin, Hu Zheng, Deng Miaoran, Ma Liang, Li Jinliang, Mai Wenjie
Siyuan Laboratory, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Key Laboratory of Nanophotonic Manipulation, Department of Physics, College of Physics & Optoelectronic Engineering, Jinan University Guangzhou 510632 China
School of Chemistry, Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, South China Normal University Guangzhou 510006 China
Chem Sci. 2025 Jul 23. doi: 10.1039/d5sc04233j.
Due to the complex fabrication process and poor reversibility of potassium (K) metal, developing high-performance host materials for K metal anodes remains a significant challenge. In this work, an ultrathin and dense N-doped carbon layer was uniformly loaded onto carbon fibers (N-CF) as a host for K metal anodes. This design effectively regulates the intrinsic adsorption behavior of metallic K, mitigating the effects of local uneven electric fields in the electrolyte and enabling stable cycling performance at high current densities. We found that the N functional groups synergistically constructed a robust potassiophilic surface, facilitating spontaneous and rapid integration with molten K. This process effectively suppresses dendrite growth and ensures stable cycling of the K metal anode, even at ultra-high current densities. Thus, the symmetric cell with the N-CF host exhibited remarkable cycling stability, maintaining stable cycling performance over 4300 h at 0.5 mA cm/0.5 mA h cm. Furthermore, the anode demonstrated a low polarization voltage and exceptional stability even at 9 mA cm, underscoring its superior dendrite inhibition capability. Ultimately, the outstanding stability of the N-CF@K metal anode enabled impressive performance in full-cell testing with a Prussian blue cathode. After 300 cycles, the full cell retained a high specific capacity of 91 mA h g and a capacity retention of 91.8% at 500 mA g. We believe that our work offers a novel chance to design an advanced host for achieving stable K metal anode performance at ultra-high current densities.
由于钾（K）金属复杂的制备工艺和较差的可逆性，开发用于K金属阳极的高性能主体材料仍然是一项重大挑战。在这项工作中，超薄且致密的氮掺杂碳层均匀地负载在碳纤维（N-CF）上，作为K金属阳极的主体。这种设计有效地调节了金属K的固有吸附行为，减轻了电解质中局部不均匀电场的影响，并在高电流密度下实现了稳定的循环性能。我们发现，N官能团协同构建了一个坚固的亲钾表面，促进了与熔融K的自发快速结合。这一过程有效地抑制了枝晶生长，并确保了K金属阳极的稳定循环，即使在超高电流密度下也是如此。因此，具有N-CF主体的对称电池表现出显著的循环稳定性，在0.5 mA cm/0.5 mA h cm下保持稳定循环性能超过4300小时。此外，即使在9 mA cm的电流密度下，该阳极也表现出低极化电压和出色的稳定性，突出了其卓越的枝晶抑制能力。最终，N-CF@K金属阳极的出色稳定性在与普鲁士蓝阴极的全电池测试中实现了令人印象深刻的性能。经过300次循环后，全电池在500 mA g的电流密度下保持了91 mA h g的高比容量和91.8%的容量保持率。我们相信，我们的工作为设计一种先进的主体材料提供了新的机会，以在超高电流密度下实现稳定的K金属阳极性能。
