J. Mater. Chem. A - Ultrathin NiO Nanosheets Anchored to A Nitrogen-Doped Dodecahedral Carbon Framework for Aqueous Potassium-Ion Hybrid Capacitors

Tianlu Wang⁺, Wei Zong⁺, Jieru Yang⁺, Leiqian Zhang, Jian Meng, Jiale Ge, Guozheng Yang, Jianguo Ren, Peng He, Elke Debroye, Jean-François Gohy, Tianxi Liu*, Feili Lai*

J. Mater. Chem. A 2024, DOI: 10.1039/D4TA01608D

Hierarchical porous structures and well-modulated interfacial interactions are essential for the performance of electrode materials. The energy storage performance can be promoted by regulating the diffusion behavior of the electrolyte and constructing a coupled interaction at heterogeneous interfaces. Herein, we have synthesized ultrathin NiO nanosheets anchored to nitrogen-doped hierarchical porous carbon (NiO/N-HPC) and applied it to construct aqueous potassium ion hybrid capacitors (APIHCs). The abundant and interconnected porous architecture promotes electrolyte penetration/diffusion and shortens the ion transport path, thereby accelerating storage reaction kinetics. The nitrogen-doped carbon support can achieve optimized metal oxides–carbon interaction and enhance the adsorption ability for the electrolyte ions, leading to earning higher storage capacity. Consequently, the prepared NiO/N-HPC exhibits a superior capacitance of 126.4 F g−1 at a current density of 0.5 A g−1, and the as-fabricated NiO/N-HPC//N-HPC APIHC achieves an ultra-high capacitance retention of 91.6% over 8000 cycles at a current density of 2 A g−1. Meanwhile, the APIHC device shows an excellent energy density of 21.95 W h kg−1 and a power density of 9000 W kg−1. 

Link: https://doi.org/10.1039/D4TA01608D