Alkaline lignin derived porous carbon as an efficient scaffold for lithium-selenium battery cathode

As one of the most abundant natural aromatic polymers with plentiful oxygen-containing groups in molecular backbones, commercial lignin can be regarded as a sustainable precursor to develop porous carbonaceous frameworks for the encapsulation of elemental selenium. In this paper, an initial combined carbonization/activation of commercial alkaline lignin and subsequent selenium-loading are adopted to fabricate serial composites of lignin-derived porous carbon (LPC) and elemental selenium (i.e., serial Se/LPC composites) for high-performance lithium-selenium (Li-Se) batteries. The high specific surface area, large pore volume and good electron conductivity of each LPC scaffold facilitate the reversible electrochemical reaction of selenium towards metallic Li, and at 0.5 C a Se/LPC composite electrode exhibits a reversible capacity of 596.4 mAh g−1 in the 2nd cycle and a capacity retention of 453.1 mAh g−1 over 300 cycles with an average decay of 0.08% per cycle. The facilely obtained microporous features of LPC scaffold, as well as the high-rate performance of corresponding Se/LPC composites (e.g., 363.2 mAh g−1, 4 C), indicate that large-scale treatment of the biomass feedstock may find its potential application in renewable green energy sources.

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