Abstract
The larger ionic radius of potassium ions than that of lithium ions significantly limits the accomplishment of rapid diffusion kinetics in graphite electrodes for potassium-ion batteries(PIBs),resulting in comparatively poor rate performance and cycle stability.Herein,we report a high-rate performance and cycling stability amorphous carbon electrode achieved through nitrogen and phosphorous co-doping.The as-prepared N,P co-doped carbon electrodes have distinct 3D structures with large surface areas,hierarchical pore architectures,and increased interlayer spaces resulting from the direct pyrolysis of supramolecular self-assembled aggregates without tem-plates.The obtained electrode N3P1 exhibits a reversible specific capacity of 258 mAh·g-1 at a current density of 0.1 A·g-1 and a good long-term cycle performance(96.1％capacity retention after 800 cycles at 0.5 A-g-1).Kinetic investigations show that the N3P1 electrode with the well-developed porous structure and large number of surface defects exhibits capacitive-driven behavior at all scan rates,which may be attributed by N and P co-doping.Ex-situ transmission electron microscopy analyses in the fully discharged and charged states demonstrate structural sta-bility and reversibility owing to the expanded interlayer space.The suggested synthesis approach is simple and effective for producing heteroatom-doped carbon materials for PIBs and other advanced electrochemical energy stor-age materials.
基金项目
National Research Foundation of Korea(NRF)from Korean government(MSIT,Korea)(2023R1A2C1005459)
Materials/Parts Technology Development Program from the Ministry of Trade,Industry,and Energy(MOTIE,Korea)(20019205)
NETL
NSTL
万方数据