A3Ti5NbO14 (A = H, Li and K) Family: Ionic Exchange, Physical and Electrochemical Properties

A new layered titanoniobate, Li3Ti5NbO14, a member of the AxM2nO4n+2 family, has been synthesized using a molten salt reaction between H3Ti5NbO14 and an eutectic “LiOH/LiNO3”. This compound crystallizes in the P21/m space group with a=9.266(1) Å, b=3.781(3) Å, c=8.95(1) Å, and b=113.9(1) ° It exhibits |Ti5NbO14| layers similar to K3Ti5NbO14, but differs from the latter by a “parallel configuration” of its |Ti5NbO5| ribbons between the two successive layers. The topotactic character of the reaction suggests that exfoliation plays a prominent role in the synthesis of this new form. This new phase intercalates reversibly 2 lithium through a first-order transformation leading to a capacity of 100 mAh/g at a potential of 1.67 V vs Li/Li + .