Lithium solid state secondary battery system

A lithium solid state secondary battery system comprising:

• a lithium solid state secondary battery comprising a cathode having a cathode active material layer and a cathode current collector, an anode having an anode active material layer and an anode current collector, and a solid electrolyte layer formed between the cathode active material layer and the anode active material layer;
• and
• an overdischarge treating unit for discharging until, in a case where a cathode potential before a cathode active material contained in the cathode active material layer emits a metal ion is regarded as Ep (V), a cathode potential becomes a lower electric potential than the Ep (V),
• wherein the anode active material layer contains an anode active material and a sulfide solid electrolyte material containing Li, A and S and having an anion structure of an ortho-composition, where A is at least one selected from the group consisting of P, Si, Ge, Al and B,
• a ratio of the anion structure of the ortho-composition is 60 mol % or more with respect to all anion structures of the sulfide solid electrolyte material, and
• the anode current collector comprises a metal.

A lithium solid state secondary battery system comprising:

• a lithium solid state secondary battery comprising a cathode having a cathode active material layer containing an active material with a battery reaction at 3 V or more with respect to an Li electric potential and a cathode current collector, an anode having an anode active material layer containing an Li-containing metal active material or a carbon active material and an anode current collector, and a solid electrolyte layer formed between the cathode active material layer and the anode active material layer;
• and
• an overdischarge treating unit for discharging a voltage of the lithium solid state secondary battery to less than 2.5 V,
• wherein the anode active material layer contains a sulfide solid electrolyte material containing Li, A and S and having an anion structure of an ortho-composition, where A is at least one selected from the group consisting of P, Si, Ge, Al and B,
• a ratio of the anion structure of the ortho-composition is 60 mol % or more with respect to all anion structures of the sulfide solid electrolyte material, and
• the anode current collector comprises a metal.