| 摘要 |
PROBLEM TO BE SOLVED: To obtain an inexpensive hexacyanoferrate complex which can reversibly and electrochemically react with lithium ion or the like in a large electrochemical reaction capacitance, by specifying composition comprising Fe3+, a metal element or atomic group, such as an alkali metal, an alkaline earth metal or a transition metal, having a smaller atomic valency than that of the Fe3+, and CN. SOLUTION: This hexacyanoferrate complex expressed by the formula: (Fe3+1-x-Mn+*)4[Fe3+(CN)6]4-y [M is a monovalent or divalent metal element, a monovalent of divalent atomic group; 1<=(n)<=2; 0<(x)<1; (y)=4(x)-(4/3)(n)(x)]. The hexacyanoferrate complex is obtained from inexpensive raw materials, and has a large electrochemical reaction capacitance. Therein, M is preferably an alkali metal, an alkaline earth metal or a transition metal, especially a metal element, such as Cu, capable of being reduced from a divalent state into a monovalent state, or an atomic group such as VO+ or NH3+. The hexacyanoferrate complex can easily be synthesized by reacting ferric chloride and a M ion-containing compound with potassium ferricyanide in water. The hexacyanoferrate complex can be used as an anodic active substance to obtain a lithium secondary battery having a large discharge capacitance and a high energy density. |
