Ultrafast reaction‐sintering of grain size‐controlled titanium niobate from TiO 2 and Nb 2 O 5

TiNb 2 O 7 is a promising alternative to graphite anodes currently employed in lithium‐ion batteries. The material offers a high specific capacity, good cycling stability, and better safety characteristics. The solid‐state reaction between TiO 2 and Nb 2 O 5 is the most straightforward synthesis route to prepare TiNb 2 O 7 . It has only been documented so far to be conducted at long periods of sintering time (>10 h). In this work, we propose a fast‐firing approach to the solid‐state synthesis, which yields TiNb 2 O 7 in less than 2 min of furnace holding time, starting from tape‐cast titania ( d 50  = 0.26 μm) and niobia ( d 50  = 0.967 μm) green compacts. Besides significantly reducing processing time, fast‐firing enabled the hindering of grain growth, producing a material with grain size ∼0.5 μm (holding time of 2 min) and ∼1 μm (5–10 min).