Electrochemical Performances And Gassing Behavior Of High Surface Area Titanium Niobium Oxides

A solvothermal synthesis is developed to build a 3D network of nanoparticles, enhancing the electrochemical performances of both TiNb2O7 and Ti2Nb10O29, especially at high current densities, with up to 190 mA h g(-1) at 10C. A set of 11 mA h pouch cells combining the nanosized TiNb2O7 with LiMn1.5Ni0.5O4 is tested and is the first to be reported for this material. Soft shell cells are used, not only to evaluate the electrochemical performances of this oxide in a larger scale battery, but also to assess its gassing behavior, a well-known limitation for application of Li4Ti5O12 in hybrid electric vehicles. In order to evaluate the sole contribution of TiNb2O7 to the swelling, an additional set of soft shell TiNb2O7/Li(Ni1/3Mn1/3Co1/3)O-2 cells is assembled and stored at 45 degrees C in a charged state. A higher swelling behavior is observed for TiNb2O7 in comparison to Li4Ti5O12; a clear trend also appears between the surface area of the oxide and the amount of gassing. The swelling of TiNb2O7 or Ti2Nb10O29 based pouch cells should be addressed before further industrial development of the two oxides can be considered.