An electrochemical battery, comprising: a. a container including a cavity that extends into the container from a cavity aperture; b. an electrochemical battery cell arranged within the cavity, wherein the electrochemical battery cell comprises a negative metal electrode, an electrolyte and a positive metal or metalloid electrode, wherein the electrolyte is arranged between the negative metal electrode and the positive metal or metalloid electrode, which electrolyte, negative metal electrode and positive metal or metalloid electrode are liquid at a temperature of the electrochemical battery cell of at least 250°C; c. a container lid assembly sealing the battery cell in the cavity, the lid assembly including an electrically conductive container lid and an electrically conductive flange, wherein the container lid covers the cavity aperture and includes a conductor aperture that extends through the container lid, wherein the electrically conductive flange (i) covers the conductor aperture, (ii) is electrically isolated from the container lid, wherein the flange is in electrical communication with the negative metal electrode, and the container lid is in electrical communication with the positive metal or metalloid electrode; d. an electrical conductor extending through the conductor aperture and electrically coupled to the negative metal electrode and the electrically conductive flange, wherein the conductor is electrically isolated from the container lid; and e. a current collector within the cavity, wherein the current collector contains the negative metal electrode and is electrically coupled to the negative metal electrode, wherein the current collector is connected to the electrical conductor, and wherein the electrical conductor is connected to the flange. a. a container including a cavity that extends into the container from a cavity aperture; b. an electrochemical battery cell arranged within the cavity, wherein the electrochemical battery cell comprises a negative metal electrode, an electrolyte and a positive metal or metalloid electrode, wherein the electrolyte is arranged between the negative metal electrode and the positive metal or metalloid electrode, which electrolyte, negative metal electrode and positive metal or metalloid electrode are liquid at a temperature of the electrochemical battery cell of at least 250°C; c. a container lid assembly sealing the battery cell in the cavity, the lid assembly including an electrically conductive container lid and an electrically conductive flange, wherein the container lid covers the cavity aperture and includes a conductor aperture that extends through the container lid, wherein the electrically conductive flange (i) covers the conductor aperture, (ii) is electrically isolated from the container lid, wherein the flange is in electrical communication with the negative metal electrode, and the container lid is in electrical communication with the positive metal or metalloid electrode; d. an electrical conductor extending through the conductor aperture and electrically coupled to the negative metal electrode and the electrically conductive flange, wherein the conductor is electrically isolated from the container lid; and e. a current collector within the cavity, wherein the current collector contains the negative metal electrode and is electrically coupled to the negative metal electrode, wherein the current collector is connected to the electrical conductor, and wherein the electrical conductor is connected to the flange.