CN2552172Y

CN2552172Y - Soft case lithium ion cell

Info

Publication number: CN2552172Y
Application number: CN02271791U
Authority: CN
Inventors: 薛建军; 唐致远; 刘建华
Original assignee: Guangzhou Great Power Battery Co ltd
Current assignee: Guangzhou Great Power Energy & Technology Co., Ltd.
Priority date: 2002-07-17
Filing date: 2002-07-17
Publication date: 2003-05-21
Anticipated expiration: 2012-07-17

Abstract

The utility model relates to a soft case lithium ion cell belonging to the battery field, comprising an anode pole piece, a cathode pole piece, an isolating film, a pole tab and a packing shell of the cell which is a compound membrane including more than three layers, wherein, the innermost layer includes polythene and polypropylene of good thermal sealing performance, the middle layer includes aluminum foil of good isolating property and the outermost layer is a multi-layered membrane layer. The sealing junction between the pole tab and the packing shell is painted with polymer hot cement resin material. The soft case lithium ion cell with simple fabrication and low cost disclosed in the utility model effectively prevents the problems of liquid leakage, air swelling and short circuit during the processes of charging, discharging and storage.

Description

Soft-casting lithium iron battery

The utility model soft-casting lithium iron battery and manufacture method belong to field of batteries, particularly relate to a kind of nonaqueous electrolyte secondary lithium battery.

In recent years, along with palmtronic, for example small and exquisite, lightweight mobile phone or laptop computer popular, to have a volume little in research and development in a large number, stable and the secondary cell of output by repeatedly charging and to use for a long time, angle from energy density, adopting lithium metal is best as the negative pole of nonaqueous electrolyte battery, lithium ion battery under the prior art, its shell almost all uses by stainless steel, the container that metal materials such as aluminium are made, yet use the battery of these sheathing material types, have to make volume of battery and weight very big, so that make nonaqueous electrolyte that the volume energy density of lithium ion battery and weight energy density are descended, and this class battery exists problems such as leakage and inside battery corrosion, uses in the high place of ask for something to be restricted.Adopt the polymer battery of similar shell with the present invention, Chinese invention patent CN 1317512A has disclosed and has adopted the manufacture method of ionic conductive polymer as electrolytical lithium ion battery and battery, it has adopted with acrylic acid fat series derivates is monomer and crosslinking agent, under thermal initiator causes, make liquid lithium ion electrolyte solution and acrylic polymer form the lithium ion polymer electrolyte material of gel state by thermochemical method, but in the polymer Li-ion battery of said method manufacturing, liquid state organic electrolyte is bound within certain scope, make the state that electrolyte is solid-state or class is solid-state, there is easy-to-leak liquid in lithium ion battery under the prior art though alleviated, problems such as corrosion, but at room temperature the conductivity of lithium ion is very low especially at low temperatures owing to polymer dielectric, make this battery mis-behave at low temperatures, especially this class battery, exist the manufacture method complexity, preparation technology requires height, makes the high deficiency of production cost of battery.

The purpose of this utility model is to improve the energy density of lithium ion battery, eliminate problems such as the easy leakage of lithium ion battery, corroding metal shell, reduce the production cost of lithium ion battery or polymer Li-ion battery, provide that a kind of preparation technology is simple, the good soft-casting lithium iron battery of low temperature performance of battery.

Lithium ion battery of the present utility model is to be main anode pole piece and cathode pole piece by the electric material that lithium ion can reversible embedding be moved out, the barrier film that separates anode pole piece and cathode pole piece, form introducing the lug be used to provide output current and the external packing housing of battery on the anodal electric current matrix and on the cathodal current matrix respectively, the external packing housing of battery is the laminated film more than three layers, innermost layer is polyethylene and the polypropylene material with good heat sealability, the aluminium foil that one deck has excellent barrier properties is contained in the centre, outermost layer is the above multi-layer thin rete with defencive function of one deck, employing has the material of defencive function, can add suitable thin layer according to different functions, the material of the defencive function of adoptable multi-layer thin rete has: PET/AI/PE; PET/AI/PP; OPP/AI/PE; PA/AI/CPP etc., external packing housing seal place at lug and battery applies hot-fusible high-molecular gum resin material, guarantee the adhesive property of the external packing housing of lug and battery, used macromolecule resin comprises: PURs such as EVA type, polyamide type, polyurethane-type, improved polyalkene, also epoxyn, synvaren, acrylate adhesive etc. be can select for use, EVA type and improved polyalkene type PUR preferentially selected for use.The present invention also is not limited to above-mentioned described PUR type macromolecule resin material.

The positive electrical material that the lithium ion that the utility model adopted can reversible embedding be moved out has: lithium hybrid transition metal oxide, transition metal are preferentially chosen from cobalt, manganese, nickel; Metal sulfide; And compound with Olive phase structure.

Be used for constituting in the main electric material of cathode pole piece, preferential selection can be carried out the material that the reversible embedding of lithium ion is moved out.In these materials, for example can preferentially use non-graphitized material with carbon element or graphite material.

Use the electric material in the above-described various both positive and negative polarity pole piece, add the material that some can play conductive capability between the reinforcement material, for the uniformity that guarantees that each material mixes in the both positive and negative polarity, can use solvent to make each components dissolved of above-mentioned composition pole piece, be made into slurry with certain viscosity.

The inside battery structure can be a winding method, is meant the centre that diffusion barrier is placed on positive electrode and negative electrode, and obtain around some center line movements continuously; Can be the lamination mode, be meant by positive electrode, negative electrode, diffusion barrier being cut into the junior unit of identical size, and junior unit stacked up continuously obtain.Can be to use barrier film.The inside battery structure that is adopted among the present invention can use any in the aforesaid way.

The external packing housing of battery is the laminated film more than three layers; innermost layer is polyethylene and the polypropylene material with good heat sealability; the aluminium foil that one deck has excellent barrier properties is contained in the centre; outermost layer is the above multi-layer thin rete with defencive function of one deck; use heat-sealable mode; formation can be wrapped and be received the space of inside battery structure; after the lug position bonding polyolefin thermosol that plays transport current; carry out heat-sealable; carry out the vacuum dehumidifying afterwards; and injection organic electrolyte material; and then it is above-mentioned with the battery vacuum sealing by fusing after the organic electrolyte activation to process; and after step such as changing into, forming final battery, it has three through the limits behind the hot melt involution.

After activating by the battery structure that multi-layer compound film surrounded with organic electrolyte, battery is carried out last pressurizing window, the machinery that seals can adopt various heat molten type sealing machines, electromagnetic induction sealing machine, ultrasonic sealing machine tool, vacuum heat molten type sealing machine, preferentially select vacuum heat molten type sealing machine for use, for solving packaged battery in the preceding process of charge and discharge cycles several times, because internal gas produces the possibility make that the internal resistance of battery strengthens, and may cause effective electric weight of battery to descend, the present invention uses the technology of sealing once more.

The present utility model has prevented that effectively battery is at charge and discharge process and storing in the process, such as battery leakage, gas rise, problem such as short circuit, improved the energy density of lithium ion battery, the low temperature performance of battery is good, comprehensive electrochemical is good, be that a kind of preparation technology is simple, the soft-casting lithium iron battery that production cost is low.

Accompanying drawing 1 is the structural representation of soft-casting lithium iron battery of the present utility model.

Accompanying drawing 2 is cut-away views of soft-casting lithium iron battery of the present utility model.

Accompanying drawing 3 is external packing shell structure schematic diagrames of soft-casting lithium iron battery of the present utility model.

Accompanying drawing 4 is lug sealing position enlarged drawings of soft-casting lithium iron battery of the present utility model.

Accompanying drawing 5 is both positive and negative polarity composite diagrams of soft-casting lithium iron battery of the present utility model.

The utility model is described in further detail below in conjunction with accompanying drawing.

As shown in Figure 1; the external packing housing of lithium ion battery of the present utility model is the laminated film more than three layers; innermost layer is polyethylene and the polypropylene material with good heat sealability; the aluminium foil that one deck has excellent barrier properties is contained in the centre; outermost layer is the above multi-layer thin rete with defencive function of one deck; use heat-sealable mode; formation can be wrapped and be received the space of inside battery structure; after the lug position bonding polyolefin thermosol that plays transport current; carry out heat-sealable; carry out the vacuum dehumidifying afterwards; and injection organic electrolyte material; and then it is above-mentioned with the battery vacuum sealing by fusing after the organic electrolyte activation to process; and after step such as changing into, form final battery 1; it has three through the limit 2 behind the hot melt involution, is introducing the lug 3a that is used to provide output current, b on the anodal electric current matrix and on the cathodal current matrix.

As shown in Figure 2, the electric material that the utility model battery can reversible embedding be moved out by lithium ion is main anode pole piece 8 and cathode pole piece 10, the barrier film 9 that separates anode pole piece and cathode pole piece, the internal structure body is wound into inside battery structure 6, introducing the lug 3a that is used to provide output current, b on the anodal electric current matrix and on the cathodal current matrix.

As shown in Figure 3, the external packing housing of lithium ion battery of the present utility model is the laminated film more than three layers, innermost layer is polyethylene and the polypropylene material 20 with good heat sealability, the aluminium foil 21 that one deck has excellent barrier properties is contained in the centre, outermost layer is the above multi-layer thin rete 22 with defencive function of one deck, use the compound agent 23 that sticks with glue between film and the film, employing has the material of defencive function, can add suitable thin layer according to different functions, the material of the defencive function of adoptable multi-layer thin rete has: PET/AI/PE; PET/AI/PP; OPP/AI/PE; PA/AI/CPP etc.

As shown in Figure 4, lug 3a of the present utility model, external packing housing 4 sealings place of b and battery apply hot-fusible high-molecular gum resin material 5, guarantee the adhesive property of the external packing housing of lug and battery, used macromolecule resin comprises: PURs such as EVA type, polyamide type, polyurethane-type, improved polyalkene, also epoxyn, synvaren, acrylate adhesive etc. be can select for use, EVA type and improved polyalkene type PUR preferentially selected for use.

As shown in Figure 5, battery of the present utility model is introduced the lug that is used to provide output current respectively on anodal electric current matrix 8 and cathodal current matrix 10, and in the centre of anode pole piece 7 and cathode pole piece 11, inserts and play the slider 9 that separates anodal and negative pole.

Claims

1; a kind of soft-casting lithium iron battery; be to be main anode pole piece and cathode pole piece by the electric material that lithium ion can reversible embedding be moved out; the barrier film that separates anode pole piece and cathode pole piece; form introducing the lug be used to provide output current and the external packing housing of battery on the anodal electric current matrix and on the cathodal current matrix respectively; it is characterized in that battery external packing housing is the laminated film more than three layers; innermost layer is polyethylene and the polypropylene material with good heat sealability; the aluminium foil that one deck has excellent barrier properties is contained in the centre; outermost layer is the above multi-layer thin rete with defencive function of one deck, applies hot-fusible high-molecular gum resin material in external packing housing seal place of lug and battery.