SnO2 nano-crystals anchored on N-doped porous carbon with enhanced lithium storage properties

Sn-based oxides have been considered as promising anode candidates for lithium-ion batteries (LIBs), but their commercialization is always impeded by severe volume expansion and unsatisfactory electron conductivity. In order to overcome these disadvantages, a novel SnO2/C nanocomposites are devised and fabricated via a 3D-network composite-gel precursors derived from macromolecule polyacrylamide, in which ultrasmall SnO2 nanocrystals ( < 10 nm) are uniformly confined in the N-doped porous carbon skeleton matrix. To generate suitable carbon coating and inherit the N-doped porous framework, mild heat treatment at 300 degrees C is used to make the carbonization process moderate, which is conducive to the formation of ultrafine SnO2 and further strengthen skeleton structure. Such a stable N-doped porous matrix allows the strengths, not only can the integrity of electrode and SnO2 nanoparticles be well maintained, but also the electronic conductivity and the quantity of active sites can be effectively promoted. As a result, this novel microstructure availably gives a reversible capability of 1011.2 mAh/g at 0.2A/g after 160 cycles and delivers a remarkable high-rate lithium storage of 357.8 mAh/g even at 12.8 A/g. Presumably, these findings may present a tactic to provide reasonable guidance for the design of metal oxide-based energy storage functional materials with huge volume variation.