| abstract |
An electrode comprising KVOPO 4 as an active ingredient, wherein the electrode is capable of electrochemical insertion and release of alkali metal ions, e.g., sodium ions. The KVOPO 4 may be milled to carbon particles to increase conductivity. A method of forming an electrode is provided, comprising milling a mixture of ammonium metavanadate, ammonium phosphate monobasic, and potassium carbonate; heating the milled mixture to a reaction temperature, and holding the reaction temperature until a solid phase synthesis of KVOPO 4 occurs; milling the KVOPO 4 together with conductive particles to form a conductive mixture of fine particles; and adding binder material to form a conductive cathode. A sodium ion battery is provided having a conductive KVOPO 4 cathode, a sodium ion donor anode, and a sodium ion transport electrolyte. The VOPO 4 , preferably has a volume greater than 90 Å 3 per VOPO 4 . |