Electrochemical element for a battery and corresponding battery
This electrochemical element for a battery, comprising a first electrode of a first polarity, a first terminal of the first polarity, a second electrode of a second polarity, a second terminal of the second polarity, and a casing comprising a first wall and a second wall. The first wall and the second wall each comprise a base body of metal and an electrically insulating layer. The electrically insulating layer comprises either a plastic coating or a layer resulting from a surface treatment. Each of the base bodies comprises a base body edge. The edges of the base bodies are joined by a weld bead to form the casing. At the location of the weld bead, the base bodies are free of the electrically insulating layer.
1 . An electrochemical cell for a battery, comprising
a first electrode of a first polarity,
a first terminal of the first polarity,
a second electrode of a second polarity,
a second terminal of the second polarity,
a casing comprising:
a first wall and a second wall, wherein the first wall and the second wall each comprise a base body made of metal and an electrically insulating layer comprising a plastic coating or a layer resulting from surface treatment, each of the base bodies comprises a base body edge, the edges of the base bodies connected by a weld bead to form the casing, and at the location of the weld bead, the base bodies are free of the electrically insulating layer;
at least one opening for a passage of the first or second terminal, the first or second terminal extending through the opening; and
an electrical insulation electrically insulating the first or second terminal from the casing, the electrical insulation comprising:
a plastic electrical insulation element extending between the first or second terminal and the casing, the plastic electrical insulation made of plastic material, and
electrically insulating spacer elements separating the first or second terminal from the casing when the plastic electrical insulation element is in a liquid state, wherein the spacer elements comprise microballs of a material having a melting temperature above the melting temperature of the plastic material and the microballs having a diameter between 100 μm and 200 μm, wherein the microballs are embedded in the plastic electrical insulation element made of solidified molten plastic material,
wherein the first or second terminal is a tab and the opening of the casing is formed by two edges of the first and second walls of the casing spaced apart from each other.
2 . The electrochemical cell for a battery according to claim 1 , wherein the metal base bodies are made of aluminium, an aluminium-based alloy, steel, stainless or nickel-plated steel.
3 . The electrochemical cell for a battery, according to claim 1 , wherein the base bodies have a thickness between 80 μm and 500 μm, or a thickness between 120 μm and 460 μm, or a thickness between 180 μm and 460 μm.
4 . The electrochemical cell for a battery according to claim 1 , wherein the second electrode comprises two electrode sheets and wherein either the second terminal is attached between the two electrode sheets or the second terminal is attached to one of the two electrode sheets and the other of the two electrode sheets is attached to one of the two electrode sheets.
5 . A battery comprising a housing and at least two electrochemical cells, wherein the electrochemical cells are each an electrochemical cell according to claim 1 , and wherein the electrochemical cells are arranged in the housing.