Flexible closure for energy storage device and energy storage device including the same

An energy storage device, comprising:

• an electrode unit including first and second current collectors that are separated by a separator;
• first and second terminals respectively connected to the first and second current collectors;
• a case accommodating the electrode unit, the case having an opening into which the electrode unit is configured to be inserted;
• and
• a flexible closure covering the opening of the case and having first and second through-holes passing therethrough and exposing the first and second terminals to the environment,
• wherein the flexible closure contains about 15 wt % or less of SiO2 and 1 wt % or less of ZnO, and wherein the flexible closure further contains at least one of the following:
• polymer having a weight percentage greater than 35 wt %, carbon having a weight percentage greater than 13.5 wt %, Al2O3 having a weight percentage greater than 17 wt % or and resin having a weight percentage greater than 4.5 wt %.

An energy storage device, comprising:

• an electrode unit including first and second current collectors that are separated by a separator;
• first and second terminals respectively connected to the first and second current collectors;
• a case accommodating the electrode unit;
• and
• a flexible closure covering the case and having first and second through-holes passing therethrough and exposing the first and second terminals to the environment, wherein the flexible closure contains SiO2 in the range of being greater than 0 wt % and less than 28 wt %.

An energy storage device, comprising:

• an electrode unit including first and second current collectors that are separated by a separator;
• first and second terminals respectively connected to the first and second current collectors;
• a case accommodating the electrode unit, the case having an opening into which the electrode unit is configured to be inserted;
• and
• a flexible closure covering the opening of the case and having first and second through-holes passing therethrough and exposing the first and second terminals to the environment, wherein the flexible closure contains SiO2 in the range of 0 wt % and less than 28 wt %, and wherein the flexible closure further contains at least one of the following:
• polymer having a weight percentage greater than 35 wt %, carbon having a weight percentage greater than 13.5 wt %, Al2O3 having a weight percentage greater than 17 wt %, or resin having a weight percentage greater than 4.5 wt %.

An energy storage device, comprising:

• an electrode unit including first and second current collectors that are separated by a separator;
• first and second terminals respectively connected to the first and second current collectors;
• a case accommodating the electrode unit, the case having an opening into which the electrode unit is configured to be inserted;
• and
• a flexible closure covering the opening of the case and having first and second through-holes passing therethrough and exposing the first and second terminals to the environment, wherein the flexible closure contains polymer, carbon, Al2O3, resin, and SiO2 in the range of 0 wt % and less than 28 wt %.