Internal gas exhaust passages forming part of the battery cover or case; Double cover vent systems

Full Title

Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells > Arrangements for facilitating escape of gases > Gas exhaust passages comprising elongated, tortuous or labyrinth-shaped exhaust passages > Internal gas exhaust passages forming part of the battery cover or case; Double cover vent systems