Secondary battery

摘要

A secondary battery typified by a lithium-ion secondary battery includes a battery outer container in which a gas release valve and positive and negative electrode external terminals are provided, an electrode group in which positive and negative plates are stacked with a separator interposed therebetween and current collection portions are provided at both ends, and positive and negative electrode current collectors forming a current path from the current collection portions of the electrode group to the positive and negative electrode external terminals, and the cross-sectional area of a gas exhaust flow channel through which gas generated inside the electrode group is discharged from the gas release valve is set so as to increase in a downstream direction.

主权项

1. A secondary battery comprising:
a battery outer container in which a gas release valve and positive and negative electrode external terminals are provided; an electrode group that includes: one or more belt-like positive plates, one or more belt-like negative plates, one or more belt-like separators, wherein the one or more belt-like positive plates are alternately stacked with the one or more belt-like negative plates with one of the one or more belt-like separators interposed therebetween to form a thin electrode group and the thin electrode group is wound along a winding axis to form a wound electrode group, wherein the wound electrode group includes: a front and a back planar portions; a first side perpendicular to the winding axis and separated along the winding axis from a second side that is parallel to the first side, a first curved portion parallel to the winding axis, a second curved portion separated along an axis perpendicular to the winding axis that is parallel to the first curved portion, a first compressed region along the first side that forms a negative electrode; a second compressed region along the second side that forms a positive electrode, a first gas flow channel internal to the first curved portion having a cross section area S1, and a second gas flow channel internal the second curved portion having a cross-sectional area S1; positive and negative electrode current collectors forming a current path from the positive electrode and the negative electrode of the electrode group to the positive and negative electrode external terminals; one or more gas exhaust flow channels communicatively connected to the first gas flow channel and the second gas flow channel, the one or more gas exhaust flow channels having a cross-sectional area S2, that is also communicatively connected to the gas release that has a cross-sectional area S3, and wherein the cross-sectional area S1 is less than the cross-sectional area S2, and the cross-sectional area S2 is less than cross-sectional area S3 so that S1