A hierarchical carbon@TiO2@MoS2 nanofibrous composite derived from cellulose substance as an anodic material for lithium-ion batteries

Abstract

A filter paper derived hierarchical carbon@TiO2@MoS2 nanofibrous composite was fabricated by employing natural cellulose substance (e.g., commercial filter paper) as both scaffold and carbon source. The nanofibers of the filter paper pre-coated with an ultrathin titania-gel film were further modified with polydiallyldimethylammonium chloride (PDDA) and polysodium-p-styrenesulfonate (PSS) polyelectrolytes based on the layer-by-layer self-assemble method. Afterwards, the composite sheet was served as a host to grow MoS2 nanosheets by a hydrothermal process. Finally, the as-prepared composite sheet was carbonized in Ar atmosphere at 800 °C for 3 h to yield the carbon@TiO2@MoS2 composite. The resultant composite consists of titania thin layer coated carbon nanofibers with wrinkled MoS2 nanosheets (with a thickness of ca. 6 nm) anchored as an external coating layer on the surfaces. When evaluated as an anodic material for lithium-ion batteries, the carbon@TiO2@MoS2 composite delivered an initial discharge capacity of 1314.4 mAhh g−1 and a stable reversible capacity of 597.2 mAhh g−1 after 100 discharge/charge cycles at the current rate of 100 mA g−1, which is higher than the theoretical capacity of the as-prepared composite electrode. The enhanced electrochemical performances of this composite were benefited from its unique three-dimensional network structures, as well as the buffering effect arising from the titania-coated carbon nanofibers, which effectively alleviates the serious volume change of MoS2 and maintains the structural integrity of the electrode during the repeated lithiation/delithiation processes.