Key Words:Lithium-ion batteries;Anodes - Electric conductivity - Hydrogenation - Lithium compounds - Nanosheets - Oxygen vacancies - Storage (materials) - Titanium compounds;Electrochemical activities - Electrochemical energy storage - Electronic conductivity - Facile solvothermal approach - High-performance lithium-ion batteries - Hydrogenation treatment - Lithium ion diffusion - Lithium storage capacity

Abstract:Ti³⁺self-doped Li<inf>4</inf>Ti<inf>5</inf>O<inf>12</inf>(S-LTO) nanosheets have been synthesized via a facile solvothermal approach combined with hydrogenation treatment. The thickness and lateral dimension of Li<inf>4</inf>Ti<inf>5</inf>O<inf>12</inf>nanosheets are 10-20 nm and 100-400 nm, respectively. The Ti³⁺species and/or oxygen vacancies are well introduced into the crystal structures of Li<inf>4</inf>Ti<inf>5</inf>O<inf>12</inf>after hydrogen reduction, resulting into an enhancement in the electronic conductivity and the modified surface electrochemical activity. When evaluated for lithium storage capacity, the S-LTO nanosheets exhibit enhanced electrochemical energy storage performances compared to the pristine Li<inf>4</inf>Ti<inf>5</inf>O<inf>12</inf>(P-LTO) nanosheets, including high capacity (165.6 mA h g^-1at 0.5 C), excellent rate capability (119.6 mA h g^-1at 20 C), and good cyclic stability (95.3% capacity retention after 100 cycles at 10 C). The improvement of lithium storage performances is ascribed to the increased electronic conductivity and the shortened lithium ion diffusion paths arising from the introduction of Ti³⁺species and the ultrathin thickness of S-LTO.<br/> © The Royal Society of Chemistry 2015.

Volume:5

Issue:30

Translation or Not:no