Toyota Jidosha Kabushiki Kaisha

Tooru Nakai

Hiroki Nagai

Satoshi Suzuki

Satomi Kawase

A battery () provided by the invention includes an electrode assembly () having a current collector forming a positive electrode and a current collector forming a negative electrode; and a flat terminal () joined to each current collector. The flat terminal () has a flat portion () including a joint area () joined to the corresponding the current collector, and the flat terminal has a first curved portion () that is formed away from the joint area along the longitudinal direction () of the flat terminal.

Battery having flat terminals

Provided is a battery capable of providing both fixing durability of a protective film during normal use and peeling easiness of the protective film during operation of a safety valve. A lithium ion secondary battery () includes a protective film () fixed to a battery case () while covering a safety valve part () including a breakable portion (). This protective film () has a first fixed portion () located around a valve-corresponding unfixed portion () and fixed to the battery case () and a second fixed portion () located more outside than the first fixed portion and fixed to the battery case () through an intermediate unfixed portion (). They are configured such that the first fixed portion () first peels off when the safety valve part () operates, prompting peeling of the second fixed portion (), thus releasing gas to the outside.

Growing community of inventors

Nagoya, Japan

Tooru Nakai