Battery case, lithium ion secondary battery, and electric vehicle

A battery shell (1) is characterized in that openings (11) are formed in the two ends of the battery shell (1) in the length direction (L) respectively, at least one cooling unit (2) extending in the length direction (L) is arranged in the battery shell (1), and a cooling liquid channel (21) allowing cooling liquid to flow through is arranged in the cooling unit (2). The at least one cooling unit (2) divides the internal space of the battery shell (1) into at least two accommodating cavities (12) which are arranged at intervals up and down along the height direction (H), and each accommodating cavity (12) is used for accommodating a battery cell (4). By arranging the cooling unit (2) in the battery shell (1), the heat generated by the battery cell (4) can be timely conducted out, so that the heat dissipation problem of the battery cell (4) in the charging and discharging process is quickly and effectively solved. Also provided are a lithium ion secondary battery (3) and an electric vehicle. 一种电池壳体(1)，所述电池壳体(1