Processes for making niobium-based electrode materials

An electrochemical cell, comprising:

• (i) an anode;
• (ii) a cathode;
• and
• (iii) an electrolyte positioned between and in contact with the anode and the cathode, wherein
• the anode comprises an anode-composition comprising an active anode species comprising at least one niobate compound, the at least one niobate compound comprising at least one transition-metal-niobate (TMN), at least one post-transition-metal-niobate (PTMN), or both, and
• the at least one niobate compound is prepared by:
• (i) providing a water-soluble niobium-containing source;
• (ii) providing a transitional metal source (TMS), a post-transitional metal source (PTMS), or both;
• (iii) dissolving (a) the water-soluble niobium-containing source, and (b) the TMS, the PTMS, or both in an aqueous medium to form an intermediate aqueous solution;
• (iv) forming an intermediate paste by admixing an inert support material with the intermediate aqueous solution, wherein the inert support material comprises a plurality of particles having an average diameter from about 5 nm to about 200 nm;
• (v) optionally coating the intermediate paste on a support substrate;
• and
• (vi) removing the inert support material by subjecting the intermediate paste to a calcination process and providing the TMN and/or the PTMN.