Battery, battery pack and electrical device

Abstract

A battery characterized in that it comprises: a housing (1) wherein an explosion protection valve (110) is provided on an outer side wall of the housing (1), wherein a first predetermined breaking line (111) is provided on the explosion protection valve (110) and wherein the area of ​​the first predetermined breaking line (111) on the explosion protection valve (110) is S1 mm²; a cell (2) arranged in the housing (1), wherein the cell (2) comprises a current collector and an active material layer (201) and wherein the ratio of the thickness of the active material layer (201) to the thickness of the current collector is X; a protective plate (3) covering the explosion protection valve (110) and arranged on a side surface of the housing (1), wherein the projection area of ​​the protective plate (3) onto the plane corresponding to the explosion protection valve (110) provided on the housing (1) is S2 mm² and wherein the mass loss rate of the protective plate (3) K1% is the amount under thermal stress;where the range of (S1*K1) / (S2*X) lies between 0.00009 and 3.2.