Biomass fallen leaves derived porous carbon for high performance lithium sulfur batteries

Rechargeable lithium-sulfur battery is considered to be one of the most promising candidates for the next-generation energy storage applications due to its high energy density, large theoretical specific capacity, low cost, and abundant sources. However, low conductivity of sulfur, shuttle effect, and volume expansion hindered its practical application. In this study, N,P co-doped hierarchical porous carbon has been fabricated from biomass fallen leaves through novel simple carbonization process with mild H₃PO₄ as an activator. By adjusting the mass ratio of H₃PO₄ and leaves, the porous carbon can be optimized to be tube-like morphology with a neatly arranged or monodispersed layout way. When serving as a sulfur host, the as-produced N,P dual-heteroatom doped porous carbon is favorable for advanced conductivity and binding polysulfides through physi-/chemisorption, so as to endow excellent electrochemical performance. An initial specific capacity of 1320 mAh·g⁻¹ can be achieved and maintained above 1000 mAh·g⁻¹ after 300 cycles at 0.1C.