Disclosed is a secondary battery in which a positive electrode active material non-covered portion is joined to a positive electrode current collector plate at one end portion of an electrode winding body, a negative electrode active material non-covered portion is joined to a negative electrode current collector plate at the other end portion of the electrode winding body, the electrode winding body has a flat surface formed by bending any one or both of the positive electrode active material non-covered portion and the negative electrode active material non-covered portion toward central axis of wound structure and overlapping the positive electrode active material non-covered portion and the negative electrode active material non-covered portion, and a groove formed in the flat surface, the positive electrode has a positive electrode cut-out portion at one end in a transverse direction of the positive electrode on a winding start side of the electrode winding body.

An electrolyte including a dinitrile compound, a trinitrile compound, and propyl propionate. Based on the total weight of the electrolyte, the weight percentage of the dinitrile compound is X, the weight percentage of the trinitrile compound is Y, and the weight percentage of the propyl propionate is Z, wherein about 2.2 wt %≤(X+Y)≤about 8 wt %, about 0.1≤(X/Y)≤about 6, 1 wt %≤Y<5 wt %, about 5 wt %≤Z≤about 50 wt %, and about 0.02<(Y/Z)≤about 0.3. The electrolyte further includes at least one selected from the group consisting of a cyclic carbonate ester having a carbon-carbon double bond, a fluorinated chain carbonate ester, a fluorinated cyclic carbonate ester, and a compound having a sulfur-oxygen double bond.

A main object of the present disclosure is to provide an all solid state battery wherein interface resistance between a current collector and an active material layer is low. In the present disclosure, the above object is achieved by providing an all solid state battery comprising: an electrode including a current collector, an electron conductive layer, and an active material layer, in this order, and a solid electrolyte layer formed on the active material layer side of the electrode, and the electron conductive layer is an agglutinate of metal particles or a metal foil, and electron conductivity of the electron conductive layer is 1×10.sup.3 S/cm or more at 25° C.

A main object of the present disclosure is to provide an all solid state battery wherein interface resistance between a current collector and an active material layer is low. In the present disclosure, the above object is achieved by providing an all solid state battery comprising: an electrode including a current collector, an electron conductive layer, and an active material layer, in this order, and a solid electrolyte layer formed on the active material layer side of the electrode, and the electron conductive layer is an agglutinate of metal particles or a metal foil, and electron conductivity of the electron conductive layer is 1×10.sup.3 S/cm or more at 25° C.

A monolithic ceramic electrochemical cell housing is provided. The housing includes two or more electrochemical sub cell housings. Each of the electrochemical sub cell housing includes an anode receptive space, a cathode receptive space, a separator between the anode receptive space and the cathode receptive space, and integrated electron conductive circuits. A first integrated electron conductive circuit is configured as an anode current collector within the anode receptive space. A second integrated electron conductive circuit is disposed as a cathode current collector within the cathode receptive space.

A monolithic ceramic electrochemical cell housing is provided. The housing includes two or more electrochemical sub cell housings. Each of the electrochemical sub cell housing includes an anode receptive space, a cathode receptive space, a separator between the anode receptive space and the cathode receptive space, and integrated electron conductive circuits. A first integrated electron conductive circuit is configured as an anode current collector within the anode receptive space. A second integrated electron conductive circuit is disposed as a cathode current collector within the cathode receptive space.

A metal-air battery from which leakage of an electrolytic solution is reduced is provided. The metal-air battery includes: a positive electrode including: a current collector; and a catalyst layer formed on the current collector and capable of reducing oxygen; a negative electrode disposed to face the positive electrode; an exterior body housing a stacked portion including the positive electrode and the negative electrode, and having an opening formed to open to the positive electrode; an electrolyte disposed inside the exterior body; and a water-repellent film covering the opening, including a joint portion joined to the exterior body, and transparent to oxygen. The catalyst layer includes a portion positioned between the joint portion and the current collector.

Provided are methods of preparing a separator/anode assembly for use in an electric current producing cell, wherein the assembly comprises an anode current collector layer interposed between a first anode layer and a second anode layer and a porous separator layer on the side of the first anode layer opposite to the anode current collector layer, wherein the first anode layer is coated directly on the separator layer.

Provided are methods of preparing a separator/anode assembly for use in an electric current producing cell, wherein the assembly comprises an anode current collector layer interposed between a first anode layer and a second anode layer and a porous separator layer on the side of the first anode layer opposite to the anode current collector layer, wherein the first anode layer is coated directly on the separator layer.

An electrolyte including a dinitrile compound, a trinitrile compound, and propyl propionate. Based on the total weight of the electrolyte, the weight percentage of the dinitrile compound is X, the weight percentage of the trinitrile compound is Y, and the weight percentage of the propyl propionate is Z, wherein, about 2.2 wt %≤(X+Y)≤about 8 wt %, about 0.1≤(X/Y)≤about 2.3, about 5 wt %≤Z≤about 50 wt %, 1 wt %<Y<5 wt %, and about 0.02≤(Y/Z)≤about 0.3; wherein wherein the dinitrile compound is one or more compounds selected from the group consisting of butanedinitrile, adiponitrile, and 1,4-dicyano-2-butene; and the trinitrile compound is one or more compounds selected from the group consisting of 1,3,6-hexanetricarbonitrile, 1,2,6-hexanetricarbonitrile and 1,2,3-tris(2-cyanoethoxy)propane.