Production process for lithium-silicate-based compound

A production process for lithium-silicate-based compound, comprising:

• reaching a lithium-silicate compound being expressed by Li2SiO3 with a transition-metal-element-containing substance including at least one member being selected from the group consisting of iron and manganese at 550° C. or less within a mixture with a molten salt including at least two alkali-metal nitrates in an atmosphere in the presence of a mixed gas including carbon dioxide and a reducing gas,
• wherein the molten salt includes lithium nitrate, and
• a lithium-silicate-based compound formed by the process is a compound expressed by the following compositional formula(1):
• Li2+a−bAbMl-xM′xSiO4+c (1)
• wherein, in formula (1), A is at least one element selected from the group consisting of Na, K, Rb and Cs;
• M is at least one element selected from the group consisting of Fe and Mn;
• M′ is at least one element selected from the group consisting of Mg, Ca, Co, Al, Ni, Nb, Ti, Cr, Cu, Zn, Zr, V, Mo and W;
• and
• the respective subscripts are specified as follows:
• 0≦×≦0.5;
• 0<a<1;
• 0≦b<0.2;
• and
• 0<c<0.3.