Foam-like, 3-dimension mesoporous N-doped carbon-assembling TiO2 nanoparticles (P25) as high-performance anode material for lithium-ion batteries

We report a controllable, low-cost and large-scale synthesis protocol for foam-like, 3-dimension mesopore N-doped carbon assembling TiO2 nanoparticles (P25). The process uses common P25 as raw material, PVP as dispersing agent and binder as well as carbon precursor, boiling bubbles as template, solidifying the boiling foam by PVP-coating-and-connecting TiO2 nanoparticles. The carbonization transforms PVP-assembling to carbon-assembling, and the obtained carbon is doped by a little N, which endows the carbon with higher conductivity. It is found that the synthesized material possesses abundant mesopores, individual nanoparticles-assembled structure and high conductive N-doped carbon matrix; shows large specific surface area and pore volume. As anode material for lithium-ion batteries (LIBs), foam-like P25 exhibits superior lithium storage properties with high discharge capacity, stable cycling performance and excellent rate capability. At 1C, foam-like P25 delivers discharge capacity of 223.1 mAh g(-1) at the 200th cycle, and average discharge capacity over 200 cycles reaches 227 mAh g(-1). These excellent electrochemical properties should be attributed to the unique foam-like mesoporous structure that greatly improves lithium storage properties of common P25, especially enhances pseudocapacitive interfacial storage of P25. The synthetic method has great potential for large scale production of foam-like P25 for practical application in high-performance LIBs.