Solid-state battery and solid-state battery group

A solid-state battery comprising:

• a battery element that includes one or more battery constitutional units, each battery constitutional unit including a positive electrode layer and a negative electrode layer facing each other and a solid electrolyte layer arranged between the positive electrode layer and the negative electrode layer;
• a protective layer covering an upper surface of an uppermost layer of the battery element, a lower surface of a lowermost layer of the battery element, and a side surface of the battery element, the protective layer including an insulating substance other than a resin;
• a positive electrode current collecting layer on a side of the positive electrode layer opposite to the solid electrolyte layer;
• and
• a negative electrode current collecting layer on a side of the negative electrode layer opposite to the solid electrolyte layer,
• wherein the protective layer covers at least one of the positive electrode current collecting layer and the negative electrode current collecting layer,
• wherein the positive electrode layer and the negative electrode layer each have an exposed portion that is not covered by the protective layer on the side surfaces of the battery element;
• and
• the positive electrode layer, the negative electrode layer, and the solid electrolyte layer constituting the battery element are not exposed to an outside of the protective layer except the exposed portions of the positive electrode layer and the negative electrode layer, and
• wherein the protective layer is in direct contact with the non-exposed ends of each of the positive electrode layer, the negative electrode layer, and the solid electrolyte layer without an interposition of another layer therebetween.