BATTERY UNIT, BATTERY MODULE AND BATTERY PACK

Abstract

The present disclosure provides a battery unit, a battery module and a battery pack. A battery pack comprises: at least one battery module; and a heating film sheet directly or indirectly heating the at least one battery module. The heating film sheet comprises a heating core and two insulating films. The heating core generates heat when the heating core is electrified, and has: a wire connection region for electrically connecting with external wires; and a heating region electrically connecting with the wire connection region, rated heating powers of different parts of the heating region are different so as to meet demand for heat of each battery module in each of different regions of the at least one battery module when the at least one battery module is heated. The two insulating films respectively cover two sides of the heating core. In the battery pack, each battery module is heated by the heating film sheet, and the rated heating powers of the different parts of the heating region of the heating core are different, so the heat provided for each battery module in the different region of the battery pack can be determined according to the demand for heat of each battery module in the different region of the battery pack, and in turn it ensures that each battery module of the battery pack is heated uniformly by the heating film sheet.

Claims

1.-35. (canceled)

36. A battery unit, comprising: one mono-battery having two end surfaces; and at least one heating film sheet, each heating film sheet being adhered to one end surface of the mono-battery; each heating film sheet comprising: a heating core generating heat when the heating core is electrified, and having: a wire connection region for electrically connecting with external wires; and a heating region electrically connecting with the wire connection region, rated heating powers of different parts of the heating region being different so as to meet demand for heat in different regions of the mono-battery when the mono-battery is heated; and two insulating films respectively covering two sides of the heating core.

37. The battery unit according to claim 36, wherein the heating region of heating core of each heating film sheet has: a first central heating region acing a middle part of the end surface of the mono-battery; and a first edge heating region provided around the first central heating region and facing a periphery of the end surface of the mono-battery.

38. A battery module, comprising: a plurality of mono-batteries arranged side by side; a box for fixing and receiving the plurality of mono-batteries; and at least one heating film sheet received in the box and contacting the plurality of mono-batteries; each heating film sheet comprising: a heating core generating heat when the heating core is electrified, and having: a wire connection region for electrically connecting with external wires; and a heating region electrically connecting with the wire connection region, rated heating power of different parts of the heating region being different so as to meet demand for heat of each mono-battery in each of different regions of the plurality of mono-batteries when the plurality of mono-batteries are heated; and two insulating films respectively covering two sides of the heating core.

39. The battery module according to claim 38, wherein each mono-battery has two end surfaces, two side surfaces and one bottom surface.

40. The battery module according to claim 39, wherein the battery module further comprises: a plurality of spacers, each spacer is provided between the two end surfaces of the two adjacent mono-batteries; one heating film sheet is provided between one end surface of each mono-battery and the corresponding spacer.

41. The battery module according to claim 40, wherein the heating region of the heating core of each heating film sheet has: a second central heating region facing a middle part of the end surface of the corresponding mono-battery; and a second edge heating region provided around the second central heating region and facing a periphery of the end surface of the corresponding mono-battery.

42. The battery module according to claim 39, wherein the heating film sheet directly contacts the side surfaces of all the mono-batteries which are arranged side by side in the battery module.

43. The battery module according to claim 42, wherein the heating region of the heating core of the heating film sheet has: a third central heating region contacting the side surfaces of the mono-batteries which are positioned in a middle part of the battery module; and two third edge heating regions provided at two sides of the third central heating region and contacting the side surfaces of the mono-batteries which are positioned at two sides of the battery module.

44. The battery module according to claim 39, wherein, the heating film sheet directly contacts the bottom surfaces of all the mono-batteries which are arranged side by side in the battery module.

45. The battery module according to claim 44, wherein the heating region of the heating core of the heating film sheet has: a fourth central heating region contacting the bottom surfaces of the mono-batteries which are positioned in a middle part of the battery module; and two fourth edge heating regions provided at two sides of the fourth central heating region and contacting the bottom surfaces of the mono-batteries which are positioned at two sides of the battery module.

46. A battery pack, comprising: at least one battery module; and a heating film sheet directly or indirectly heating the at least one battery module (M); the heating film sheet comprising: a heating core generating heat when the heating core is electrified, and having: a wire connection region for electrically connecting with external wires; and a heating region electrically connecting with the wire connection region, rated heating powers of different parts of the heating region being different so as to meet demand for heat of each battery module in each of different regions of the at least one battery module when the at least one battery module is heated; and two insulating films respectively covering two sides of the heating core.

47. The battery pack according to claim 46, wherein the heating film sheet is provided to a bottom of the at least one battery modules and directly heats each battery module.

48. The battery pack according to claim 47, wherein the heating region of the heating core of the heating film sheet has: a fifth central heating region contacting each battery module which is positioned in a middle part of the battery pack; and two fifth edge heating regions provided at two sides of the fifth central heating region and contacting the battery modules which are positioned at two sides of the battery pack.

49. The battery pack according to claim 46, wherein the battery pack further comprises: an air cooling assembly provided to a bottom of the at least one battery module.

50. The battery pack according to claim 49, wherein the heating film sheet is provided under the air cooling assembly and indirectly heats the at least one battery module via the air cooling assembly.

51. The battery pack according to claim 50, wherein the heating region of the heating core of the heating film sheet has: a sixth central heating region contacting a middle part of the air cooling assembly; and two sixth edge heating regions provided at two sides of the sixth central heating region and contacting two sides of the air cooling assembly.

52. The battery pack according to claim 46, wherein the battery pack further comprises: a liquid cooling assembly provided to a bottom of the at least one battery module.

53. The battery pack according to claim 52, wherein the heating film sheet is provided under the liquid cooling assembly and indirectly heats the at least one battery module via the liquid cooling assembly.

54. The battery pack according to claim 53, wherein the liquid cooling assembly comprises a plurality of liquid cooling tubes which form a cooling circuit, each liquid cooling tube contacts a bottom surface of each mono-battery of the battery modules which is positioned above each liquid cooling tube; the two adjacent liquid cooling tubes contact one heating film sheet which is positioned under the two adjacent liquid cooling tubes.

55. The battery pack according to claim 54, wherein the heating region of the heating core of each heating film sheet has: a seventh central heating region corresponding to one liquid cooling tube of the two adjacent liquid cooling tubes and contacting a middle part of the one liquid cooling tube; two seventh edge heating region provided at two sides of the seventh central heating region and contacting two sides of the one liquid cooling tube; an eighth central heating region corresponding to the other liquid cooling tube of the two adjacent liquid cooling tube and contacting a middle part of the other liquid cooling tube; and two eighth edge heating regions provided at two sides of the eighth central heating region and contacting two sides of the other liquid cooling tube; the wire connection region of the heating core of each heating film sheet has: a first wire connection region electrically connecting with the seventh central heating region; and a second wire connection region electrically connecting with the eighth central heating region; the heating core of each heating film sheet further has: a bridge region for electrically connecting the seventh central heating region and the eighth central heating region.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0016] FIG. 1 is a schematic diagram of a method of an external PTC heating in the prior art;

[0017] FIG. 2 is a schematic diagram of a method of the hot air heating in the prior art;

[0018] FIG. 3 is a perspective view of a battery unit according to the present disclosure;

[0019] FIG. 4 is a perspective view of a heating film sheet of the battery unit according to the present disclosure;

[0020] FIG. 5 is a schematic diagram of a heating core of the heating film sheet in FIG. 4;

[0021] FIG. 6 is a perspective view of an embodiment of a battery module according to the present disclosure, in which a box is omitted and the heating film sheet contacts an end surface of a mono-battery;

[0022] FIG. 7 is a schematic diagram of a heating core of the heating film sheet in FIG. 6;

[0023] FIG. 8 is a perspective view of another embodiment of the battery module according to the present disclosure, in which the heating film sheet contacts side surfaces of mono-batteries;

[0024] FIG. 9 is a schematic diagram of a heating core of the heating film sheet in FIG. 8;

[0025] FIG. 10 is a perspective view of still another embodiment of the battery module according to the present disclosure, in which a heating film sheet contacts bottom surfaces of mono-batteries;

[0026] FIG. 11 is a schematic diagram of a heating core of the heating film sheet in FIG. 10;

[0027] FIG. 12 is a perspective view of an embodiment of a battery pack according to the present disclosure, in which a heating film sheet directly contacts a battery module;

[0028] FIG. 13 is a schematic diagram of a heating core of a heating film sheet in FIG. 12;

[0029] FIG. 14 is a perspective view of another embodiment of the battery pack according to the present disclosure, in which a heating film sheet contacts a battery module via an air cooling assembly;

[0030] FIG. 15 is a schematic diagram of a heating core of the heating film sheet in FIG. 14;

[0031] FIG. 16 is a perspective view of still another embodiment of the battery pack according to the present disclosure, in which a heating film sheet contacts a battery module via a liquid cooling assembly;

[0032] FIG. 17 is a schematic diagram of a heating core of a heating film sheet in FIG. 16.

[0033] Reference numerals are represented as follows: [0034] E battery unit [0035] M battery module [0036] P battery pack [0037] 1 mono-battery [0038] 11 end surface [0039] 12 side surface [0040] 13 bottom surface [0041] 2 box [0042] 21 end plate [0043] 22 side plate [0044] 23 top plate [0045] 3 heating film sheet [0046] 31 heating core [0047] 311 wire connection region [0048] 3111 first wire connection region [0049] 3112 second wire connection region [0050] 312 heating region [0051] 3121 first central heating region [0052] 3122 first edge heating region [0053] 3123 second central heating region [0054] 3124 second edge heating region [0055] 3125 third central heating region [0056] 3126 third edge heating region [0057] 3127 fourth central heating region [0058] 3128 fourth edge heating region [0059] 3129 fifth central heating region [0060] 312A fifth edge heating region [0061] 312B sixth central heating region [0062] 312C sixth edge heating region [0063] 312D seventh central heating region [0064] 312E seventh edge heating region [0065] 312F eighth central heating region [0066] 312G eighth edge heating region [0067] 313 bridge region [0068] 32 insulating film [0069] 4 air cooling assembly [0070] 5 liquid cooling assembly [0071] 51 liquid cooling tube [0072] 6 spacer [0073] 7 tank [0074] 8 PTC heater [0075] 9 heat exchanger [0076] 10 pump [0077] A hot air heater [0078] B blower [0079] C battery pack case [0080] W wire [0081] D arrangement direction

DETAILED DESCRIPTION

[0082] Hereinafter a battery unit, a battery module and a battery pack according to the present disclosure will be described in detail in combination with the figures.

[0083] Firstly, a battery unit according to a first aspect of the present disclosure will be described.

[0084] Referring to FIGS. 3-5, a battery unit E according to the present disclosure comprises: one mono-battery 1 having two end surfaces 11; and at least one heating film sheet 3, each heating film sheet 3 is adhered to one end surface 11 of the mono-battery 1. Each heating film sheet 3 comprises a heating core 31 and two insulating films 32. The heating core 31 generates heat when the heating core 31 is electrified, and has: a wire connection region 311 for electrically connecting with external wires W; and a heating region 312 electrically connecting with the wire connection region 311, rated heating powers of different parts of the heating region 312 are different, so as to meet demand for heat in different regions of the mono-battery 1 when the mono-battery 1 is heated. The two insulating films 32 respectively cover two sides of the heating core 31.

[0085] In addition, it should be noted that, the rated heating powers of the different parts of the heating region 312 are determined by thermal simulation analysis and test validation optimization.

[0086] In the battery unit E according to the present disclosure, the end surface 11 of the mono-battery 1 is heated by the heating film sheet 3, and the rated heating powers of the different parts of the heating region 312 of the heating core 31 are different, so heat provided for the different regions of the mono-battery 1 can be determined according to demand for heat in the different regions of the mono-battery 1, and in turn it ensures that the mono-battery 1 is uniformly heated by the heating film sheet 3.

[0087] In the battery unit E according to the present disclosure, referring to FIG. 5, in an embodiment, the heating region 312 of the heating core 31 of each heating film sheet 3 has: a first central heating region 3121 facing a middle part of the end surface 11 of the mono-battery 1; and a first edge heating region 3122 provided around the first central heating region 3121 and facing a peripheral of the end surface 11 of the mono-battery 1.

[0088] In the battery unit E according to the present disclosure, in an embodiment, a rated heating power of the first edge heating region 3122 is higher than a rated heating power of the first central heating region 3121.

[0089] In the battery unit E according to the present disclosure, in an embodiment, a ratio of the rated heating power of the first edge heating region 3122 to the rated heating power of the first central heating region 3121 is 2:1.

[0090] Secondly, a battery module according to a second aspect of the present disclosure will be described.

[0091] Referring to FIGS. 6-11, a battery module M according to the present disclosure comprises: a plurality of mono-batteries 1 arranged side by side; a box 2 for fixing and receiving the plurality of mono-batteries 1; and at least one heating film sheet 3 received in the box 2 and contacting the plurality of mono-batteries 1. Each heating film sheet 3 comprises a heating core 31 and two insulating films 32. The heating core 31 generates heat when the heating core 31 is electrified, and has: a wire connection region 311 for electrically connecting with external wires W; and a heating region 312 electrically connecting with the wire connection region 311, rated heating powers of different parts of the heating region 312 are different, so as to meet demand for heat of each mono-battery in each of different regions of the plurality of mono-batteries 1 when the plurality of mono-batteries 1 are heated. The two insulating films 32 respectively cover two sides of the heating core 31.

[0092] In the battery module M according to the present disclosure, each mono-battery 1 of the battery module M is heated by the heating film sheet 3, and the rated heating powers of the different parts of the heating region 312 of the heating core 31 are different, so heat provided for each mono-battery 1 in the different region of the battery module M can be determined according to the demand for heat of each mono-battery 1 in the different region of the battery module M, and in turn it ensures that each mono-battery 1 of the battery module M is uniformly heated by the heating film sheet 3.

[0093] In the battery module M according to the present disclosure, referring to FIG. 6, FIG. 8 and FIG. 10, in an embodiment, each mono-battery 1 has two end surfaces 11, two side surfaces 12 and one bottom surface 13.

[0094] In the battery module M according to the present disclosure, referring to FIG. 6, in an embodiment, the battery module M further comprises: a plurality of spacers 6, each spacer 6 is provided between the two end surfaces 11 of the two adjacent mono-batteries 1; one heating film sheet 3 is provided between one end surface 11 of each mono-battery 1 and the corresponding spacer 6.

[0095] In the battery module M according to the present disclosure, referring to FIG. 7, in an embodiment, the heating region 312 of the heating core 31 of each heating film sheet 3 has: a second central heating region 3123 facing a middle part of the end surface 11 of the corresponding mono-battery 1; and a second edge heating region 3124 provided around the second central heating region 3123 and facing a periphery of the end surface 11 of the corresponding mono-battery 1.

[0096] In the battery module M according to the present disclosure, in an embodiment, a rated heating power of the second edge heating region 3124 is higher than a rated heating power of the second central heating region 3123.

[0097] In the battery module M according to the present disclosure, in an embodiment, a ratio of the rated heating power of the second edge heating region 3124 to the he rated heating power of the second central heating region 3123 is 2:1.

[0098] In the battery module M according to the present disclosure, referring to FIG. 8, in an embodiment, the heating film sheet 3 contacts with the side surfaces 12 of all the mono-batteries 1 which are arranged side by side in the battery module M.

[0099] In the battery module M according to the present disclosure, referring to FIG. 9, in an embodiment, the heating region 312 of the heating core 31 of the heating film sheet 3 has: a third central heating region 3125 contacting the side surfaces 12 of the mono-batteries 1 which are positioned in a middle part of the battery module M; and two third edge heating regions 3126 provided at two sides of the third central heating region 3125 and contacting the side surfaces 12 of the mono-batteries 1 which are positioned at two sides of the battery module M.

[0100] In the battery module M according to the present disclosure, in an embodiment, a rated heating power of the third edge heating region 3126 is higher than a rated heating power of the third central heating region 3125.

[0101] In the battery module M according to the present disclosure, in an embodiment, a ratio of the rate heating power of the third edge heating region 3126 to the rate heating power of the third central heating region 3125 is 2:1.

[0102] In the battery module M according to the present disclosure, referring to FIG. 10, in an embodiment, the heating film sheet 3 contacts the bottom surfaces 13 of all the mono-batteries 1 which are arranged side by side in the battery module M.

[0103] In the battery module M according to the present disclosure, referring to FIG. 11, in an embodiment, the heating region 312 of the heating core 31 of the heating film sheet 3 has: a fourth central heating region 3127 contacting the bottom surfaces 13 of the mono-batteries 1 which are positioned in a middle part of the battery module M; and two fourth edge heating regions 3128 provided at two sides of the fourth central heating region 3127 and contacting the bottom surfaces 13 of the mono-batteries 1 which are positioned at two sides of the battery module M.

[0104] In the battery module M according to the present disclosure, in an embodiment, a rated heating power of the fourth edge heating region 3128 is higher than a rated heating power of the fourth central heating region 3127.

[0105] In the battery module M according to the present disclosure, in an embodiment, a ratio of the rated heating power of the fourth edge heating region 3128 to the rated heating power of the fourth central heating region 3127 is 2:1.

[0106] In the battery module M according to the present disclosure, referring to FIG. 8 and FIG. 10, in an embodiment, the box 2 comprises: two end plates 21; two side plates 22 fixed and connected to the two end plates 21; and one top plate 23 fixed and connected to the two end plates 21 and the two side plates 22 from above.

[0107] Finally, a battery pack according to a third aspect of the present disclosure will be described.

[0108] Referring to FIGS. 12-17, a battery pack P according to the present disclosure comprises: at least one battery module M; and a heating film sheet 3 directly or indirectly heating the at least one battery module M. The heating film sheet 3 comprises a heating core 31 and two insulating films 32. The heating core 31 generates heat when the heating core 31 is electrified, and has: a wire connection region 311 for electrically connecting with external wires W; and a heating region 312 electrically connecting with the wire connection region 311, rated heating powers of different parts of the heating region 312 are different so as to meet demand for heat of each battery module M in each of different regions of the at least one battery module M when the at least one battery module M is heated. The two insulating films 32 respectively cover two sides of the heating core 31.

[0109] In the battery pack P according to the present disclosure, each battery module M in the battery pack P is heated by the heating film sheet 3, and the rated heating powers of the different parts of the heating region 312 of the heating core 31 are different, so heat provided for each battery module M in the different region of the battery pack P can be determined according to the demand for heat of each battery module M in the different region of the battery pack P, and in turn it ensures that each battery module M of the battery pack P is uniformly heated by the heating film sheet 3.

[0110] In the battery pack P according to the present disclosure, referring to FIG. 12, in an embodiment, the heating film sheet 3 is provided to a bottom of the at least one battery module M and directly heats each battery module M.

[0111] In the battery pack P according to the present disclosure, referring to FIG. 13, in an embodiment, the heating region 312 of the heating core 31 of the heating film sheet 3 has: a fifth central heating region 3129 contacting each battery module M which is positioned in a middle part of the battery pack P; and two fifth edge heating regions 312A provided at two sides of the fifth central heating region 3129 and contacting the battery modules M which are positioned at two sides of the battery pack P.

[0112] In the battery pack P according to the present disclosure, in an embodiment, a rated heating power of the fifth edge heating region 312A is higher than a rated heating power of the fifth central heating region 3129.

[0113] In the battery pack P according to the present disclosure, in an embodiment, a ratio of the rated heating power of the fifth edge heating region 312A to the fifth central heating region 3129 is 2:1.

[0114] In the battery pack P according to the present disclosure, referring to FIG. 14, in an embodiment, the battery pack. P further comprises: an air cooling assembly 4 provided to a bottom of the at least one battery module M.

[0115] In the battery pack P according to the present disclosure, referring to FIG. 14, in an embodiment, the heating film sheet 3 is provided under the air cooling assembly 4 and indirectly heats the at least one battery module M via the air cooling assembly 4.

[0116] In the battery pack P according to the present disclosure, referring to FIG. 15, in an embodiment, the heating region 312 of the heating core 31 of the heating film sheet 3 has: a sixth central heating region 312B contacting a middle part of the air cooling assembly 4; and two sixth edge heating regions 312C provided at two sides of the sixth central heating region 312B and contacting two sides of the air cooling assembly 4.

[0117] In the battery pack P according to the present disclosure, in an embodiment, a rated heating power of the sixth edge heating region 312C is higher than a rated heating power of the sixth central heating region 312B.

[0118] In the battery pack P according to the present disclosure, in an embodiment, a ratio of the rated heating power of the sixth edge heating region 312C to the rated heating power of the sixth central heating region 312B is 2:1.

[0119] In the battery pack P according to the present disclosure, referring to FIG. 16, in an embodiment, the battery pack P further comprises: a liquid cooling assembly 5 provided to a bottom of the at least one battery module M.

[0120] In the battery pack P according to the present disclosure, referring to FIG. 16, in an embodiment, the heating film sheet 3 is provided under the liquid cooling assembly 5 and indirectly heats the at least one battery module M via the liquid cooling assembly 5.

[0121] In the battery pack P according to the present disclosure, referring to FIG. 16, in an embodiment, the liquid cooling assembly 5 comprises a plurality of liquid cooling tubes 51 which form a cooling circuit, each liquid cooling tube 51 contacts the bottom surface 13 of each mono-battery 1 of the battery module M which is positioned above each liquid cooling tube 51, correspondingly, the two adjacent liquid cooling tubes 51 contact one heating film sheet 3 which is positioned under the two adjacent liquid cooling tubes 51.

[0122] In the battery pack P according to the present disclosure, referring to FIG. 17, in an embodiment, the heating region 312 of the heating core 31 of each heating film sheet 3 has: a seventh central heating region 312D corresponding to one liquid cooling tube 51 of the two adjacent liquid cooling tubes 51 and contacting a middle part of the one liquid cooling tube 51; two seventh edge heating regions 312E provided at two sides of the seventh central heating region 312D and contacting two sides of the one liquid cooling tube 51; a eighth central heating region 312F corresponding to the other liquid cooling tube 51 of the two adjacent liquid cooling tubes 51 and contacting a middle part of the other liquid cooling tube 51; and two eighth edge heating regions 312G provided at two sides of the eighth central heating region 312F and contacting two sides of the other liquid cooling tube 51. Correspondingly, the wire connection region 311 of the heating core 31 of each heating film sheet 3 has: a first wire connection region 3111 electrically connecting with the seventh central heating region 312D; and a second wire connection region 3112 electrically connecting with the eighth central heating region 312F. Correspondingly, the heating core 31 of each heating film sheet 3 further has: a bridge region 313 for electrically connecting the seventh central heating region 312D and the eighth central heating region 312F.

[0123] In the battery pack P according to the present disclosure, in an embodiment, a rated heating power of the seventh edge heating region 312E is higher than a rated heating power of the seventh central heating region 312D, a rated heating power of the eighth edge heating region 312G is higher than a rated heating power of the eighth central heating region 312F.

[0124] In the battery pack P according to the present disclosure, referring to FIG. 17, in an embodiment, a ratio of the rated heating power of the seventh edge heating region 312E to the rated heating power of the seventh central heating region 312D is 2:1; a ratio of the rated heating power of the eighth edge heating region 312G to the rated heating power of the eighth central heating region 312F is 2:1.

[0125] A working temperature in any one aspect of the battery unit E, the battery module M and battery pack P is −40° C.˜120° C.

[0126] The insulating film 32 of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P is made of insulating silica gel, polyimide or Teflon.

[0127] An insulation resistance of the insulating film 32 of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P is 1000V/50 MΩ.

[0128] A thickness of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P is 0.5 mm˜3 mm.

[0129] A thickness of the insulating film 32 of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P is 0.08 mm˜2 mm.

[0130] The insulating film 32 of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P is made of insulating silica gel, and the thickness of the insulating film 32 is 0.2 mm˜2 mm.

[0131] The insulating film 32 of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P is made of polyimide, and the thickness of the insulating film 32 is 0.08 mm˜0.3 mm.

[0132] The two insulating films 32 of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P cover and seal the heating core 31 by way of binder, hot pressing or weft knitting.

[0133] The insulating film 32 of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P is made of polyimide and the binder uses a double-sided adhesive tape of 3M.

[0134] A thickness of each adhesive layer in the heating film sheet 3 in any one aspects of the battery unit E, the battery module M and the battery pack P is equal to or less than 0.15 mm.

[0135] The heating core 31 of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P is made of copper, silver, graphite, PTC, nickel chromium alloy, stainless steel or composite materials of them.

[0136] The rated heating powers of the different parts of the heating region 312 of the heating core 31 of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P are changed by one process of spraying powder, changing a sectional area of a metal through which a current flows, or changing a density per unit area of an internal material which generates heat. The process of spraying powder uses graphite powder, and adopts an automatic coating machine with a set path of coating, a flow of coating and the region of coating so as to control the requirements of powers in the different parts. The process of changing the sectional area of the metal through which the current flows uses a technology of laser structuring or the process of chemical precipitation setting, so as to realize varied specifications of a metal conductive path width. The process of changing the density per unit area of the material which generates heat uses a method of arrangement configuration, for example, metal conductors are arranged densely for a region of high heating power density, and metal conductors are arranged sparsely in a region of low heating power density.

[0137] The connection between the wire connection region 311 and the external wire W in any one aspect of the battery unit E, the battery module M and the battery pack P is by means of riveting and then welding with tin.

[0138] A pulling force which a welding joint between the wire connection region 311 and the external wire W in any one aspect of the battery unit E, the battery module M and the battery pack P bears is more than 150 N.

[0139] The external wire W in any one aspect of the battery unit E, the battery module M and the battery pack P uses two leads. The two leads can improve the current capability and the reliability of connection, and also can reduce the thermal resistance of connection so as to reduce heat generated.

[0140] The rated heating power of the wire connection region 311 of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P is equal to or less than 0.05 W/cm.sup.2.

[0141] A range of the rated heating power of the heating region 312 of the heating film sheet 3 in any one aspect of the battery unit E, the battery module M and the battery pack P is 0.5 W/cm.sup.2˜2 W/cm.sup.2.