Porous nanocomposites by cotton-derived carbon/NiO with high performance for lithium-ion storage

Biomass materials have attracted extensive attention in functional composites because of the unique mi-crostructure, renewability and electrochemical performance. Herein, porous NiO/C composites were synthesized through a hydrothermal reaction and calcination using cellulose-rich natural cotton as carbon source. The BET specific surface area of NiO/C composites was calculated to be 314.4 m(2) g(-1) basing on the Brunauer-Emmett-Teller model. As the LIB anode, NiO/C composites presented a high specific capacity of 727 mA h g(-1) over 150 cycles at 100 mA g(-1). Increasing the current density to 2 A g(-1), enabled the specific capacity of NiO/C the electrode to reach 476 mA h g(-1). Obviously, the unique nanostructure and synergistic effect of NiO and carbonaceous matrix made NiO/C composites exhibit the excellent lithium storage performance. The NiO/C composites are interconnected with each other and form nanopores leading to the large specific surface area, enabling the enhancement of electrolyte diffusion and providing additional routes for ion diffusion. In addition, the hybridized carbon substrate can mitigate the volume expansion and external bending stress of NiO/C composites during the lithiation/delithiation process. (C) 2021 Elsevier B.V. All rights reserved.