Battery cell, battery, and electric apparatus
A battery cell, including a housing, a pressure relief member disposed on a first wall of the housing, an electrode assembly disposed inside the housing, an electrolyte immersing the electrode assembly, and a sealing member and an active substance that are disposed inside the housing. The sealing member is configured to seal the active substance on a side of electrode assembly close to the first wall. The sealing member is configured to be actuated when an internal pressure or temperature of the battery cell reaches a first threshold, to release the active substance, and the active substance is able to react with the electrolyte and/or the electrode assembly to increase the internal pressure or temperature of the battery cell, so as to actuate the pressure relief member. The battery cell can quickly discharge its internal temperature and pressure when experiencing thermal runaway, and the battery cell has good safety performance.
1 . A battery cell, comprising:
a housing, comprising a housing body and an end cover;
a pressure relief member disposed on the end cover;
an electrode assembly disposed inside the housing;
an electrolyte, immersing the electrode assembly;
a sealing member; and
an active substance,
wherein
the sealing member is configured to seal the active substance to the end cover on a side of the end cover facing the electrode assembly; and
the sealing member is configured to be actuated when an internal pressure or temperature of the battery cell reaches a first threshold, to release the active substance, so that the active substance reacts with the electrolyte and/or the electrode assembly to increase the internal pressure or temperature of the battery cell; and
wherein the active substance comprises at least one of:
potassium dichromate,
sodium hypochlorite,
lead dioxide,
periodic acid,
cobaltic fluoride, and
sodium ferrate.
2 . The battery cell according to claim 1 , wherein the pressure relief member is configured to be actuated when the internal pressure or temperature of the battery cell reaches a second threshold, wherein the second threshold is greater than the first threshold.
3 . The battery cell according to claim 1 , wherein the sealing member seals the active substance at a location of the end cover corresponding to the pressure relief member.
4 . The battery cell according to claim 3 , wherein
the end cover is provided with a pressure relief hole that is covered by both the pressure relief member and the sealing member, the sealing member is disposed on a side of the pressure relief member close to the electrode assembly; and
the sealing member, the pressure relief member, and hole walls of the pressure relief hole jointly define an enclosed space for accommodating the active substance.
5 . The battery cell according to claim 4 , wherein both the pressure relief member and the sealing member are sheet-shaped.
6 . The battery cell according to claim 3 , wherein the sealing member is made of an insulating material and the sealing member is disposed between the end cover and the electrode assembly, to insulate and isolate the electrode assembly from the active substance.
7 . The battery cell according to claim 6 , wherein the sealing member is provided with a first accommodating chamber corresponding to a location of the pressure relief member, and at least part of the active substance is sealed in the first accommodating chamber.
8 . The battery cell according to claim 7 , wherein the first accommodating chamber is provided with a first opening, and the first opening is jointly enclosed by the end cover and the pressure relief member.
9 . The battery cell according to claim 7 , wherein
the end cover is in a rectangular shape, the sealing member is further provided with two second accommodating chambers, and in a length direction of the end cover, the two second accommodating chambers are separately located on two sides of the first accommodating chamber; and
one part of the active substance is sealed in the first accommodating chamber while the other part of the active substance is sealed in the two second accommodating chambers.
10 . The battery cell according to claim 9 , wherein each second accommodating chamber is provided with a second opening, and the second opening is enclosed by the end cover.
11 . A battery, comprising the battery cell according to claim 1 .
12 . An electric apparatus, comprising the battery according to claim 11 .