Sponge-like porous carbon/tin composite anode materials for lithium ion batteries

A novel sponge-like porous C/Sn composite is synthesized by dispersing SnO2 nanoparticles into a soft-template polymer matrix followed by carbonization. The mesoporous C/Sn anodes can deliver a capacity as high as 1300 mAh g−1 after 450 charge/discharge cycles, and provide a capacity of 180 mAh g−1 even at 4000 mA g−1 charge/discharge current density. An extra reversible capacity over the theoretical value of the porous C/Sn anode is observed, which is attributed to the reversible formation/decomposition of the gel-like polymers formed on the mesoporous C/Sn composite due to the catalytic effect of the Sn nanoparticles. The high capacity, long cycle life, high power, ∼100% Coulombic efficiency, and inexpensive production method make the sponge-like porous C/Sn composite an attractive anode material in Li-ion batteries for electric vehicles and renewable energy storage.