An electrochemical cell, comprising: a) a ceramic casing, comprising: i) a first ceramic substrate having a first peripheral edge extending to and meeting with opposed first substrate outer and inner major faces; ii) a first ring-shaped metallization contacting the first substrate inner major face adjacent to the first substrate peripheral edge; iii) a second ceramic substrate having a second substrate peripheral edge extending to and meeting with opposed second substrate outer and inner major faces; iv) a second ring-shaped metallization contacting the second substrate inner major face adjacent to the second substrate peripheral edge; and v) a gold layer hermetically sealing the first and second ring-shaped metallizations together to thereby hermetically seal the first and second ceramic substrates to each other; b) a first electrode current collector contacting the first substrate inner major face, spaced inwardly from the first ring-shaped metallization; c) a first electrode active material contacting the first electrode current collector; d) a second electrode current collector contacting the first substrate inner major face, spaced inwardly from the first ring-shaped metallization, wherein the second electrode current collector is side-by-side with the first electrode current collector; e) a solid electrolyte contacting the first electrode active material; f) a second electrode active material contacting the second electrode current collector and contacting the solid electrolyte opposite the first electrode active material; g) a first opening extending through the first ceramic substrate in alignment with the first electrode current collector, wherein a first gold body hermetically sealed to the first ceramic substrate in the first opening conductively contacts the first electrode current collector to thereby serve as a first terminal; and h) a second opening extending through the first ceramic substrate in alignment with the second electrode current collector, wherein a second gold body hermetically sealed to the first ceramic substrate in the second opening conductively contacts the second electrode current collector to thereby serve as a second, opposite polarity terminal for the electrochemical cell. a) a ceramic casing, comprising: i) a first ceramic substrate having a first peripheral edge extending to and meeting with opposed first substrate outer and inner major faces; ii) a first ring-shaped metallization contacting the first substrate inner major face adjacent to the first substrate peripheral edge; iii) a second ceramic substrate having a second substrate peripheral edge extending to and meeting with opposed second substrate outer and inner major faces; iv) a second ring-shaped metallization contacting the second substrate inner major face adjacent to the second substrate peripheral edge; and v) a gold layer hermetically sealing the first and second ring-shaped metallizations together to thereby hermetically seal the first and second ceramic substrates to each other; i) a first ceramic substrate having a first peripheral edge extending to and meeting with opposed first substrate outer and inner major faces; ii) a first ring-shaped metallization contacting the first substrate inner major face adjacent to the first substrate peripheral edge; iii) a second ceramic substrate having a second substrate peripheral edge extending to and meeting with opposed second substrate outer and inner major faces; iv) a second ring-shaped metallization contacting the second substrate inner major face adjacent to the second substrate peripheral edge; and v) a gold layer hermetically sealing the first and second ring-shaped metallizations together to thereby hermetically seal the first and second ceramic substrates to each other; b) a first electrode current collector contacting the first substrate inner major face, spaced inwardly from the first ring-shaped metallization; c) a first electrode active material contacting the first electrode current collector; d) a second electrode current collector contacting the first substrate inner major face, spaced inwardly from the first ring-shaped metallization, wherein the second electrode current collector is side-by-side with the first electrode current collector; e) a solid electrolyte contacting the first electrode active material; f) a second electrode active material contacting the second electrode current collector and contacting the solid electrolyte opposite the first electrode active material; g) a first opening extending through the first ceramic substrate in alignment with the first electrode current collector, wherein a first gold body hermetically sealed to the first ceramic substrate in the first opening conductively contacts the first electrode current collector to thereby serve as a first terminal; and h) a second opening extending through the first ceramic substrate in alignment with the second electrode current collector, wherein a second gold body hermetically sealed to the first ceramic substrate in the second opening conductively contacts the second electrode current collector to thereby serve as a second, opposite polarity terminal for the electrochemical cell.