An adhesive film for metal terminals is interposed between a metal terminal connected to an electrode of a power storage device element and a power storage device external member, and includes, a first polyolefin layer, a substrate, and a second polyolefin layer disposed on the metal terminal side. A sea-island structure is observed in a sectional image of the first polyolefin layer in a direction parallel to TD, the sectional image being obtained in the range of up to 30% of the thickness of the first polyolefin layer. In the sectional image, after the adhesive film for metal terminals is left to stand for 12 seconds in a heated and pressurized environment in which the temperature is 190° C. and the surface pressure is 0.016 MPa, and then left for one hour at 25° C., the of the total area of the island portions of the sea-island structure is 25.0% to 35.0%.

This electrical storage device comprises: an electrode body; a bottomed cylindrical outer can; a sealing plate to which a positive electrode terminal and a negative electrode terminal are attached; and a functional part placed near the positive electrode terminal or the negative electrode terminal on the inner surface of the sealing plate. The electrode body has a positive electrode tab group for which a plurality of positive electrode tabs are laminated, and a negative electrode tab group for which a plurality of negative electrode tabs are laminated, and each tab group functions as a spring that connects the electrode body and the sealing plate. Of the positive electrode tab group and the negative electrode tab group, the spring constant of one tab group near the functional part is greater than the spring constant of the other tab group.

This electrical storage device comprises: an electrode body; a bottomed cylindrical outer can; a sealing plate to which a positive electrode terminal and a negative electrode terminal are attached; and a functional part placed near the positive electrode terminal or the negative electrode terminal on the inner surface of the sealing plate. The electrode body has a positive electrode tab group for which a plurality of positive electrode tabs are laminated, and a negative electrode tab group for which a plurality of negative electrode tabs are laminated, and each tab group functions as a spring that connects the electrode body and the sealing plate. Of the positive electrode tab group and the negative electrode tab group, the spring constant of one tab group near the functional part is greater than the spring constant of the other tab group.

The present disclosure provides a battery module, including a first battery cell arrangement structure, a second battery cell arrangement structure and a bus bar array. With battery cells stacked in a horizontal direction, a first battery cell arrangement structure and a second battery cell arrangement structure are stacked in a vertical direction, and a first bus bar of a bus bar array is used to sequentially connect the battery cells of the first battery cell arrangement structure and the second battery cell arrangement structure. As a result, a total positive electrode and a total negative electrode of a battery module are located at two ends of the battery module, which greatly reduces the possibility of a short circuit of the battery module and improves the safety of the battery module.

The present disclosure provides a battery module, including a first battery cell arrangement structure, a second battery cell arrangement structure and a bus bar array. With battery cells stacked in a horizontal direction, a first battery cell arrangement structure and a second battery cell arrangement structure are stacked in a vertical direction, and a first bus bar of a bus bar array is used to sequentially connect the battery cells of the first battery cell arrangement structure and the second battery cell arrangement structure. As a result, a total positive electrode and a total negative electrode of a battery module are located at two ends of the battery module, which greatly reduces the possibility of a short circuit of the battery module and improves the safety of the battery module.

The disclosure provides a flexible and rechargeable battery unit that is configured to a free-form shape, and/or configured to include uneven thickness, thereby providing multi-axial coverage and/or enhanced bendability and storage capacity. The battery unit and method for fabricating the battery unit includes cathode and anode substrates configured in a free-form shape, a separator layer made from a nanofiber material for enclosing either the cathode substrate or the anode substrate to form an enclosed cathode substrate or enclose anode substrate, with the enclosed cathode substrate being overlapped with the anode substrate, or the enclosed anode substrate being overlapped with the cathode substrate to form a stacked battery structure, which can be further configured to form a notched battery structure. The stacked battery structure or the notched battery structure, which can be expanded, is subsequently injected with an electrolyte and closed using a packaging layer to form a battery pouch structure.

The disclosure provides a flexible and rechargeable battery unit that is configured to a free-form shape, and/or configured to include uneven thickness, thereby providing multi-axial coverage and/or enhanced bendability and storage capacity. The battery unit and method for fabricating the battery unit includes cathode and anode substrates configured in a free-form shape, a separator layer made from a nanofiber material for enclosing either the cathode substrate or the anode substrate to form an enclosed cathode substrate or enclose anode substrate, with the enclosed cathode substrate being overlapped with the anode substrate, or the enclosed anode substrate being overlapped with the cathode substrate to form a stacked battery structure, which can be further configured to form a notched battery structure. The stacked battery structure or the notched battery structure, which can be expanded, is subsequently injected with an electrolyte and closed using a packaging layer to form a battery pouch structure.

A rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a case connected to the first electrode and accommodating the electrode assembly, the case including an opening to receive the electrode assembly; a cap plate bonded to the case to cover an outer region of the opening and including a through-hole to expose a center region of the opening; a terminal plate bonded to and insulated from the cap plate, covering the through-hole, and connected to the second electrode; and a terminal plating layer coated on an upper surface of the terminal plate, and a thickness of a center portion of the terminal plating layer overlapping the through-hole is thicker than a thickness of an outer portion of the terminal plating layer overlapping the upper surface of the terminal plate.

A rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a case connected to the first electrode and accommodating the electrode assembly, the case including an opening to receive the electrode assembly; a cap plate bonded to the case to cover an outer region of the opening and including a through-hole to expose a center region of the opening; a terminal plate bonded to and insulated from the cap plate, covering the through-hole, and connected to the second electrode; and a terminal plating layer coated on an upper surface of the terminal plate, and a thickness of a center portion of the terminal plating layer overlapping the through-hole is thicker than a thickness of an outer portion of the terminal plating layer overlapping the upper surface of the terminal plate.

A secondary battery includes a battery device, a container member, a cover member, and an electrode terminal. The battery device includes a positive electrode and a negative electrode. The container member contains the battery device inside. The cover member is welded to the container member. The electrode terminal is provided in the cover member. The cover member includes a recessed part formed by the cover member bending to protrude in part toward the inside of the container member. The electrode terminal is disposed inside the recessed part.