Electrocatalytic Cathodes Based on Cobalt Nanoparticles Supported on Nitrogen-Doped Porous Carbon by Strong Electrostatic Adsorption for Advanced Lithium-Sulfur Batteries
ENERGY & FUELS(2020)
摘要
Energy demands have increased rapidly over the previous decades, leading to new innovations in the energy storage field. One of the candidates for advanced energy storage is the lithium-sulfur battery. This Li-S battery is advantageous for its relatively high volumetric and gravimetric energy density and affordability. However, the widespread use and manufacturing of Li-S batteries are hampered by accelerated capacity decay upon cycling due to volume changes at the cathode, a "shuttle effect" of soluble lithium polysulfide (LPS) dissolution from cathode, and kinetically sluggish redox processes. In this study, we have designed a new and unique electrocatalytic cathode composed of ultrasmall cobalt nanoparticles embedded into nitrogen-doped porous carbon to host sulfur for the application of Li-S batteries via strong electrostatic adsorption (SEA). The large surface area (SA(BET) = 2355 m(2) g(-1)) and uniform distribution of ultrafine cobalt nanoparticles embedded in the nitrogen-doped carbon composite enables a high sulfur loading and significantly immobilizes soluble LPS during battery cycling while improving the electrochemical performance through catalytic effects. A sulfur doping of 71 wt % was attained, affording an initial specific capacity of 1219 mAh g(-1) at 0.1 degrees C (1C = 1675 mAh g(-1)) and Coulombic efficiency (99.1%) due to the cathodic multifunctional arrangements. At 0.5 degrees C, the battery initially yields a specific capacity of 968 mAh g(-1) and decreases to 858 mAh g-1 after 100 cycles. The battery delivered a specific capacity of 579 mAh g(-1) after 300 cycles at 1 C and an exceptionally low capacity fade of 0.07% per cycle. This study demonstrates that SEA can be utilized to incorporate highly active metal nanoparticles into sulfur hosts to advance their electrocatalytic function and thereby advance Li-S batteries' stability.
更多查看译文
关键词
cobalt nanoparticles,lithium–sulfur batteries,strong electrostatic adsorption,porous carbon,advanced lithium–sulfur,nitrogen-doped
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要