CN214477788U

CN214477788U - Composite diaphragm for wound battery and wound battery

Info

Publication number: CN214477788U
Application number: CN202022721230.0U
Authority: CN
Inventors: 赵梁栋; 王明煜; 徐松
Original assignee: Henan Chaoli New Energy Co ltd
Current assignee: Henan Chaoli New Energy Co ltd
Priority date: 2020-11-23
Filing date: 2020-11-23
Publication date: 2021-10-22
Anticipated expiration: 2030-11-23

Abstract

The utility model relates to a coiling formula battery is with compound diaphragm and coiling formula battery belongs to battery technical field. The utility model discloses a compound diaphragm for coiled battery, including the diaphragm, the one end of diaphragm bonds there is the sticky tape, the sticky tape includes diaphragm bonding portion, isolation part, the electrically conductive bonding portion that sets gradually along sticky tape length direction, diaphragm bonding portion bonds with one side of the corresponding tip of diaphragm, bonds on the electrically conductive bonding portion and has electrically conductive foil material, electrically conductive foil material is metal foil material or graphite film or graphite alkene film; the isolation part is used for bonding with the surface of the corresponding pole piece. The utility model discloses a coiling formula is compound diaphragm for battery bonds in diaphragm one end and sets up the electrically conductive foil material, when preparing coiling formula battery, can make the electrically conductive foil material be in the outmost of electric core, avoids ion and metal casing reaction on the negative pole piece, and the electrode material layer on the pole piece of the protection laminating mutually is difficult for droing with it, and the diaphragm and the electrically conductive foil material of still being convenient for are fixed a position.

Description

Composite diaphragm for wound battery and wound battery

Technical Field

The utility model relates to a coiling formula battery is with compound diaphragm and coiling formula battery belongs to battery technical field.

Background

The winding type cylindrical battery has an irreplaceable position in the battery market due to the unique shape and the highly mature manufacturing process, particularly, in the fields of civil consumer batteries and batteries for electric tools, the cylindrical winding type secondary battery occupies an important position in the market for a long time due to the unique advantages of the cylindrical winding type secondary battery, the battery core of the winding type battery sequentially comprises a pole piece (a positive pole piece or a negative pole piece), a diaphragm, a pole piece (a negative pole piece or a positive pole piece) and the diaphragm from inside to outside, and the stability of the battery core is high.

Wound cells typically employ a metal casing, such as a steel can. When the battery is designed, the negative plate is usually positioned on the outer side of the battery core, and the positive plate is positioned on the inner side of the negative plate. At this time, in order to avoid the reaction between the negative electrode material on the negative electrode sheet and the metal material of the battery case, a layer of separator is usually wound outside the battery cell. However, the porous structure of the membrane easily causes part of the ions to pass through the membrane to react with the metal shell.

SUMMERY OF THE UTILITY MODEL

The utility model provides a coiling formula battery is with compound diaphragm and coiling formula battery can reduce the ion on the negative pole piece and battery metal casing reaction.

The utility model adopts the technical scheme as follows:

a composite diaphragm for a winding type battery comprises a diaphragm, wherein one end of the diaphragm is bonded with an adhesive tape, the adhesive tape comprises a diaphragm bonding part, an isolation part and a conductive bonding part which are sequentially arranged along the length direction of the adhesive tape, the diaphragm bonding part is bonded with one side of the corresponding end part of the diaphragm, a conductive foil is bonded on the conductive bonding part, and the conductive foil is a metal foil or a graphite film or a graphene film; the isolation part is used for bonding with the surface of the corresponding pole piece.

The diaphragm is a single-layer diaphragm, a multi-layer co-extrusion diaphragm or a multi-layer composite diaphragm.

The utility model provides a coiling type battery, includes casing and the coiling type electricity core of setting in the casing, the coiling type electricity core includes positive plate, negative pole piece, diaphragm, its characterized in that, the diaphragm is foretell composite membrane, electrically conductive foil is located the outmost of coiling type electricity core.

The sum of the lengths of the isolation part and the conductive foil is larger than the perimeter of the winding type battery cell.

The coiled battery is a zinc-nickel secondary battery or a zinc-manganese secondary battery.

The utility model discloses a coiling formula is composite diaphragm for battery bonds in diaphragm one end and sets up electrically conductive foil, when preparing coiling formula battery, can make electrically conductive foil be in the outmost of electric core, utilizes electrically conductive foil to avoid ion and metal casing reaction on the negative pole piece on the one hand, and on the other hand can also protect the electrode material layer on the pole piece of laminating mutually with it and be difficult for droing. Moreover, when the winding type battery is processed, the composite diaphragm is convenient for the diaphragm and the conductive foil to be positioned.

The conductive foil is bonded at the end part corresponding to the diaphragm through the adhesive tape, the isolating part is reserved between the two sections of the adhesive tape, and the isolating part is bonded with the surface of the corresponding pole piece, so that the stability of the relative position of the diaphragm and the pole piece can be further improved.

Drawings

Fig. 1 is a schematic perspective view of a composite separator according to example 1;

fig. 2 is a schematic structural diagram of a battery cell of a wound battery in embodiment 5.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects solved by the present invention easier to understand, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1

As shown in fig. 1, the composite diaphragm of the present embodiment includes a diaphragm 1, one end of the diaphragm is connected to a conductive foil 2, and the conductive foil is a metal foil. Specifically, the thickness of the diaphragm is larger than that of the metal foil,

one surface (e.g., the upper surface) of the metal foil near the end of the separator is flush with one surface (the upper surface) of the separator near the end of the metal foil, and an adhesive tape 3 is attached to the flush surfaces. Specifically, one end of the adhesive tape is attached to the corresponding surface of one end of the corresponding metal foil, and the other end of the adhesive tape is attached to the corresponding surface of the diaphragm. The end of the tape bonded to the membrane constitutes the membrane bonded portion of the tape, which can be considered as the first bonded portion, and the end of the metal foil bonded constitutes the conductive bonded portion of the tape, which can be considered as the second bonded portion. The portion of the tape between the membrane bond and the conductive bond of the tape constitutes the separator of the tape.

The diaphragm can be a single-layer diaphragm, a multi-layer co-extrusion diaphragm or a multi-layer composite diaphragm. Specifically, the single-layer diaphragm is a PP diaphragm, a PE diaphragm or a cellulose diaphragm, the multi-layer co-extrusion diaphragm is a PP-PE-PP co-extrusion diaphragm, and the multi-layer composite diaphragm is a PP-PE double-layer composite diaphragm, a PP-PE-PP three-layer composite diaphragm, a non-woven fabric-PP film three-layer composite film or a PP film-non-woven fabric-PP film three-layer composite film. The non-woven fabric is PP non-woven fabric, PE non-woven fabric or cellulose non-woven fabric, and the diaphragm can also be directly single-layer non-woven fabric, such as PP non-woven fabric or cellulose non-woven fabric.

The metal foil is a steel foil, a copper foil or a tin foil, and can also be a tinned copper foil, a copper-plated steel foil, a tinned steel foil or a copper-plated tinned steel foil, wherein the copper-plated tinned steel foil is formed by plating copper on one surface and plating tin on the other surface of the steel foil.

The tin-plated copper foil is obtained by plating tin on one surface or two surfaces of copper foil, and the obtained tin-plated copper foil comprises a copper layer and a tin layer coated on one surface or two surfaces of the copper layer. Accordingly, the other copper-plated steel foil, tin-plated steel foil, and copper-plated tin-plated steel foil have a structure similar to that of tin-plated copper foil.

The thicknesses of the diaphragm, the conductive foil and the adhesive tape can be selected according to requirements, preferably, the thickness of a single-layer diaphragm is 6 micrometers to 60 micrometers, the thickness of a multi-layer diaphragm is 30 micrometers to 1000 micrometers, the thickness of the conductive foil is 6 micrometers to 60 micrometers, and the thickness of the adhesive tape is 6 micrometers to 100 micrometers.

Example 2

This embodiment is different from embodiment 1 in that the thickness of the separator is equal to that of the metal foil.

Example 3

This embodiment differs from embodiment 1 in that the adhesive tape may be replaced with an adhesive layer and a separator layer bonded together, that is, an adhesive layer is provided on one side of the separator near one end of the metal foil and on the corresponding side of the metal foil near one end of the separator, a separator layer is provided on a surface of the adhesive layer remote from the separator and the metal foil, and a separator layer is bonded on a surface of the adhesive layer.

Example 4

The present embodiment is different from embodiment 1 in that the conductive foil is a graphite film or a graphene film.

Example 5

As shown in fig. 2, the winding battery of the present embodiment is a winding zinc-nickel battery, and includes a cylindrical casing, a battery cell and an electrolyte solution, where the battery cell is a cylindrical winding battery cell. The battery core is formed by winding a positive plate 4, a negative plate 5 and a diaphragm, wherein the positive plate comprises a positive current collector and a positive material layer coated on two surfaces of the positive current collector, and the negative plate comprises a negative current collector and a negative material layer coated on two surfaces of the negative current collector. The separator was the composite separator in example 1 above.

Specifically, the composite diaphragm including the diaphragm and the metal foil is folded in half from the middle to form two diaphragm ends. And then clamping the negative plate in the middle of the folded diaphragm, and then overlapping a positive plate on the outer surface of the diaphragm on one side of the negative plate, wherein the diaphragm attached to the positive plate is the diaphragm end which is not connected with the metal foil. And then sequentially winding the positive plate, the diaphragm, the negative plate and the diaphragm from inside to outside to form the battery cell. In the prepared battery core, the outermost layer is made of metal foil, and the sum of the lengths of the metal foil and the adhesive tape isolating part in the length direction of the diaphragm is larger than the perimeter of the battery core, so that the battery core (the battery core without the metal foil) can be completely wrapped by the metal foil and the isolating part for a circle. The outermost end of the negative plate is tightly attached to the inner surface of the metal foil, the inner surface of the negative plate is tightly attached with a diaphragm (the diaphragm end which is not connected with the metal foil), and the inner surface of the diaphragm end which is not connected with the metal foil is tightly attached with a positive plate. At the moment, in the battery core, the adhesive tape at the joint of the diaphragm of the composite diaphragm and the metal foil is positioned at the outer side, and the adhesive coated surface of the adhesive tape isolation part is bonded on the outer surface of the corresponding negative plate.

The total length of the copper foil and the adhesive tape is as follows: the purpose is to prevent the contact of the zinc cathode and the steel shell and prevent the penetration of zinc ions and the reaction of the steel shell.

The wound cells of examples 6 to 8 were different from those of example 5 in that the composite separators of examples 2 to 4 were used, respectively.

Claims

1. The composite diaphragm for the wound battery comprises a diaphragm and is characterized in that one end of the diaphragm is bonded with an adhesive tape, the adhesive tape comprises a diaphragm bonding part, an isolation part and a conductive bonding part which are sequentially arranged along the length direction of the adhesive tape, the diaphragm bonding part is bonded with one side of the corresponding end part of the diaphragm, a conductive foil is bonded on the conductive bonding part, and the conductive foil is a metal foil or a graphite film or a graphene film; the isolation part is used for bonding with the surface of the corresponding pole piece.

2. The composite separator for a rolled battery according to claim 1, wherein the separator is a single-layer separator, a multi-layer co-extruded separator, or a multi-layer composite separator.

3. A coiled battery comprises a shell and a coiled battery cell arranged in the shell, wherein the coiled battery cell comprises a positive plate, a negative plate and a diaphragm, and the coiled battery cell is characterized in that the diaphragm is the composite diaphragm of any one of claims 1-2, and the conductive foil is positioned on the outermost layer of the coiled battery cell.

4. A wound battery as claimed in claim 3, wherein the sum of the length of the separator and the conductive foil is greater than the circumference of the wound cell.

5. A jelly-roll battery according to claim 3, wherein the jelly-roll battery is a zinc-nickel secondary battery or a zinc-manganese secondary battery.