A method of assembling a battery pack from a plurality of battery cells of a same type is provided. The method may account for normal variation in the DC internal resistance of the cells and thereby improve the battery pack's performance. The method comprises: identifying a design for at least a portion of a battery pack, wherein the portion includes a plurality of battery cells and the design defines, for each of the plurality of cells, a cell position within the portion of the battery pack; obtaining a thermal model for the portion of the battery pack.

A battery temperature control system includes: a refrigeration cycle including a compressor and a heat exchanger; an accumulator; a condenser; a bypass for supplying refrigerant discharged from the compressor to the heat exchanger while bypassing the condenser; a valve mechanism; a temperature detector; a controller configured to switch the valve mechanism; and an introduction passage branched off from a passage extending from a discharge port of the compressor to a position in the refrigeration cycle upstream of the heat exchanger. The introduction passage supplies the refrigerant reduced in pressure to a part of a passage extending from a position in the refrigeration cycle downstream of the accumulator or downstream of the heat exchanger to a position in the refrigeration cycle upstream of the accumulator. The controller adjusts an opening degree of the variable throttle disposed in the introduction passage depending on a temperature detected by the temperature detector.

A heat transfer medium is used for a heat transfer system configured to transfer a cold of a refrigerant circulating through a refrigeration cycle device to an electric device. The heat transfer medium includes water and a lower alcohol that is at least one of methanol or ethanol.

A partition member having a thickness direction and a plane direction perpendicular to the thickness direction, partitioning single cells, or a single cell and a member other than a single cell, in the thickness direction, including a liquid and a thermal insulating material capable of retaining the liquid, and an external package housing the thermal insulating material and the liquid, having an area (S1) of an internal space of the external package and an area (S2) of the thermal insulating material in plane view of the external package and the thermal insulating material in the thickness direction, a thickness (D1) of the thermal insulating material, and a volume (V1) of the liquid that satisfy the relationship of the following expression 1 and/or the following expression 2, and a battery assembly using the same.

0.25≤V1/(S1×D1)≤0.70  expression 1:

0.35≤S2/S1  expression 2:

A partition member that has a high opening temperature, and can properly switch the thermal resistance before and after opening, and a battery assembly can be provided.

A partition member having a thickness direction and a plane direction perpendicular to the thickness direction, partitioning single cells, or a single cell and a member other than a single cell, in the thickness direction, including a liquid and a thermal insulating material capable of retaining the liquid, and an external package housing the thermal insulating material and the liquid, having an area (S1) of an internal space of the external package and an area (S2) of the thermal insulating material in plane view of the external package and the thermal insulating material in the thickness direction, a thickness (D1) of the thermal insulating material, and a volume (V1) of the liquid that satisfy the relationship of the following expression 1 and/or the following expression 2, and a battery assembly using the same.

0.25≤V1/(S1×D1)≤0.70  expression 1:

0.35≤S2/S1  expression 2:

A partition member that has a high opening temperature, and can properly switch the thermal resistance before and after opening, and a battery assembly can be provided.

The present disclosure provides a battery module and a battery pack. The battery pack comprises a box and a battery module, the battery module is accommodated in the box. The battery module comprises batteries sequentially arranged in a first direction. The battery comprises an electrode assembly, a case and a cap assembly, the electrode assembly is received in the case, and the cap assembly is connected with the case. The case comprises two first side walls, and the two first side walls are respectively positioned at two sides of the electrode assembly in the first direction. The first side walls of two adjacent batteries face each other. An area of the first side wall is defined as S.sub.1, a distance between the electrode assemblies of two adjacent batteries in the first direction is defined as D, S.sub.1 and D satisfying a relationship:
1.2×10.sup.−5 mm.sup.−1≤D/S.sub.1≤500×10.sup.−5 mm.sup.−1.

A heat-insulating sheet includes a fiber sheet having spaces therein and silica xerogel held in the spaces of the fiber sheet. The heat-insulating sheet includes a first region located at a peripheral portion of the heat-insulating sheet and a second region surrounded by the first region. A compression rate of the second region of the heat-insulating sheet in response to a pressure of 1 MPa applied to the second region is smaller than a compression rate of the first region of the heat-insulating sheet in response to a pressure of 1 MPa applied to the first region. The heat-insulating sheet reduces a compressive strain while maintaining heat insulation performance.

The heat-insulating sheet may be installed in a secondary battery and enhances reliability of the secondary battery against a swell of the battery due to an increase of pressure inside a cell of the battery.

A heat-insulating sheet includes a fiber sheet having spaces therein and silica xerogel held in the spaces of the fiber sheet. The heat-insulating sheet includes a first region located at a peripheral portion of the heat-insulating sheet and a second region surrounded by the first region. A compression rate of the second region of the heat-insulating sheet in response to a pressure of 1 MPa applied to the second region is smaller than a compression rate of the first region of the heat-insulating sheet in response to a pressure of 1 MPa applied to the first region. The heat-insulating sheet reduces a compressive strain while maintaining heat insulation performance.

The heat-insulating sheet may be installed in a secondary battery and enhances reliability of the secondary battery against a swell of the battery due to an increase of pressure inside a cell of the battery.

An electrified vehicle powered by a traction battery includes a coolant loop arranged to convey coolant through at least a radiator, a chiller, and the traction battery to transfer heat from the battery. The vehicle also includes a refrigerant loop in fluid communication with the chiller to selectively circulate refrigerant through the chiller to provide supplemental heat transfer from coolant conveyed through the chiller. The vehicle further includes a vision system having at least one camera with a field of view including a vicinity of the radiator and a controller programmed to detect a radiator coolant leak based on image data output from the vision system. The controller is also programmed to cause a bypass of the radiator within the coolant loop to stop conveyance of coolant through the radiator in response to detecting a coolant leak.

This disclosure provides a design method for a radiator of a vehicle power module. The design method includes: selecting a plurality of specific values from the possible value ranges of the first distance D1, the second distance D2 and the radius R, respectively, to form different combinations of the plurality of specific values, performing simulation calculations on the different combinations, and obtaining a temperature rise ΔTj and a pressure drop ΔPf corresponding to each combination to form a plurality of samples; through a response surface method, fitting explicit functions of the temperature rise ΔTj and the pressure drop ΔPf with the first distance D1, the second distance D2 and the radius R as dependent variables; and through a multi-objective optimization, determining the first distance D1, the second distance D2 and the radius R with an optimization objective that the temperature rise ΔTj and the pressure drop ΔPf are simultaneously minimized.