A kind of novel lithium battery with super thin metal shell
Technical field
The present invention relates to technical field of lithium batteries, and in particular to a kind of novel lithium battery with super thin metal shell.
Background technique
In recent years, increasingly sharpening with environmental pollution, New Energy Industry increasingly receive the concern of people.And lithium ion
Important component of the power battery as electric vehicle, the performances such as security performance, energy density and cycle life are by direct shadow
The popularization and use of electric vehicle are rung, thus cause extensive concern.
Currently, there are mainly three types of the shell mechanism of form, cylindrical type steel shells, square aluminum for lithium-ion-power cell on the market
Shell or steel shell, aluminum-plastic composite membrane flexible package.The common model 18650 of cylindrical type steel shell power battery, the battery of this model
Shell is standard size, is easy to scale of mass production, so that the manufacturing cost of manufacture single battery is reduced, but due to 18650 electricity
The single capacity in pond is small, and an electric vehicle needs a large amount of single battery to be gone here and there and combined, to increase further battery significantly
The complexity and cost of the assembling of mould group and power-supply management system (BMS);Rectangular aluminum hull or steel shell power battery are to compare at present
A kind of shell mechanism relatively generallyd use adds since rectangular aluminum hull or the generally single battery core capacity of steel shell power battery are bigger
The heat transfer heating conduction of upper metal shell is relatively good, therefore the assembling manufacture difficulty and cost phase of further battery mould group and BMS
Lower than cylindrical type steel shell power battery, power battery factory mostly domestic at present is using this type of structure, but rectangular aluminum hull or steel
The outer casing thickness of shell is difficult to do thin, and the aluminum hull lower than 0.6mm thickness is difficult to solve due to will appear various problems in use
It is not available certainly, therefore shell occupies biggish volumetric spaces, the energy density of single battery core leads to entire battery with relatively low
The energy force density of packet is promoted limited;Aluminum-plastic composite membrane flexible-packed battery, as the term suggests be using aluminum-plastic composite membrane as battery core outside
The power battery of shell material, maximum feature is due to its sheathing material very thin (0.1mm is even as thin as 0.06mm) and monomer
The volume of battery core can be made very big, the energy density highest of single battery core, simultaneously because aluminum-plastic composite membrane flexible package is in battery core
Overcharge or other security exception situations such as internal short-circuit inside only will appear shell slight bulging when producing gas, in big volume production gas
Also the case where hot composite package mouth in edge is exhausted decompression, is generally not in explosion only can be broken through, is three kinds of shell mechanisms
The relatively highest one kind of middle safety.But the processing and manufacturing technical threshold of plastic-aluminum combined membrane material itself is higher, for a long time by day
This Showa electrician and two company of DNP occupy most of market, and cost also remains high, and in addition aluminum-plastic composite membrane is due to its structure
Ectonexine be polymer, heat transfer heat-conducting effect is poor, therefore is typically necessary in the modular structure of flexible-packed battery
Increase heat-conducting plate or coldplate, so that a large amount of space reductions mould group group efficiency is occupied, so while flexible packaging power is electric
The single cell energy density highest in pond, but in groups after the whole capability density of battery pack there is no what advantages.Therefore, existing
Three kinds of shell mechanisms having respectively have advantage and disadvantage, respectively have choice.
Summary of the invention
In order to solve the above technical problems, the present invention provides a kind of novel lithium battery with super thin metal shell, using this
The power battery that super thin metal shell is produced have higher energy density height, good heat dissipation effect, safety, high package strength and
High electrolyte resistance corrosion resistance, long-term reliability be good and the more low advantage of cost.
To reach above-mentioned purpose, the present invention adopts the following technical scheme:
A kind of novel lithium battery with super thin metal shell, including super thin metal shell and be located at super thin metal shell in
The naked battery core in portion, the naked battery core include anode pole piece, cathode pole piece, isolation film, positive pole ear, negative lug, electrolyte, institute
It states and is equipped with thermoplastic polymer sealant between positive pole ear, negative lug and super thin metal shell;The super thin metal shell
Including super thin metal plate layer, the surface of the super thin metal plate layer is coated with high heat conductive insulating coating.
Further, the thermoplastic polymer sealant include positive pole ear heat melt sealant and negative lug heat melt it is close
Sealing, positive pole ear heat melt sealant include the adhesive layer of positive pole ear and thermoplastic polymer, thermoplastic polymer with it is ultra-thin
The hot melt fused layer of the adhesive layer of metal shell, positive pole ear and super thin metal shell;It includes negative that negative lug heat, which melts sealant,
The adhesive layer of pole tab and thermoplastic polymer, the adhesive layer of thermoplastic polymer and super thin metal shell, negative lug and super
The hot melt fused layer of thin metal shell.
Further, the high heat conductive insulating coating includes the high thermal conductivity coating and electronic isolation coating, and the height is led
Hot coating is graphite-like heat conducting film or heat conductive silica gel class heat conducting film, and electronic isolation coating is that resistivity is greater than 1010The nothing of Ω m
Machine object or polymer.Further, the high heat conductive insulating coating is high heat conductive insulating composite coating, and the high heat conductive insulating is multiple
Closing coating is the graphite heat conducting composite membrane or graphene heat conduction composite membrane that outer surface is covered with PET.
Further, the super thin metal shell with a thickness of 0.02-0.2mm.
Further, the super thin metal shell with a thickness of 0.05-0.15mm.
Further, the super thin metal plate layer uses stainless steel or aluminium alloy, and the stainless steel is austenite stainless
The double item stainless steels of steel, ferritic stainless steels, austenite ferrite it is any, the aluminium alloy be 1 be fine aluminium, 1 be that aluminium closes
Gold, 3 be alumal, 5 be almag, 6 be any of alusil alloy.
Further, which is characterized in that at the non-positive pole ear of the naked battery core, negative lug with super thin metal shell it
Between by welding encapsulate.
Further, the thermoplastic polymer sealant includes at least one of PP, CPP, and being melted by extruder is one
Body extrusion is prepared.
By adopting the above technical scheme, it has the following technical effect that
1, the novel lithium battery with super thin metal shell of the invention, using super thin metal shell, so that the novel lithium
Battery had both had the high leakproofness and mechanical strength of rectangular aluminum-shell battery shell, was conducive in power battery During Process of Long-term Operation
Reliability and durability, while also having safety and the thickness ultrathin of aluminum-plastic composite membrane flexible-packed battery shell, to reduce
The space that non-effective battery component occupies;
2, the novel lithium battery with super thin metal shell of the invention, super thin metal shell is also equipped with good thermally conductive
Property, promotion and the battery of energy density can be taken into account in the mould group space that further reduction conducting-heat elements occupy in the process in groups
Heat dissipation performance, while the cost of sheathing material also has certain advantage compared with existing property material for battery shell;
3, the present invention has the novel lithium battery of super thin metal shell, positive pole ear, negative lug and super thin metal shell
Between electronics isolation carried out by thermoplastic polymer sealant, prevent positive pole ear, negative lug by super thin metal shell
Conducting forms short circuit.
Detailed description of the invention
Fig. 1 is the structural schematic diagram that the novel lithium battery with super thin metal shell of the invention is not yet packaged;
Fig. 2 is that the multilayer of super thin metal shell of the invention disassembles schematic diagram;
Fig. 3 is the structural schematic diagram after the novel lithium battery encapsulation with super thin metal shell of the invention;
In figure: for super thin metal shell -10;Super thin metal plate layer -11;High thermal conductivity coating -12;Electronic isolation coating -13;
Naked battery core -20;Positive pole ear -21;Negative lug -22;Positive pole ear heat melts sealant -31;Negative lug heat melts sealant-
32。
Specific embodiment
With reference to the accompanying drawings and detailed description, the present invention is described in detail.
In conjunction with Fig. 1-3, the present invention provides a kind of novel lithium battery with super thin metal shell, including super thin metal shell
10 and positioned at super thin metal interior of shell naked battery core 20, naked battery core includes anode pole piece, cathode pole piece, isolation film, positive pole
Ear 21, negative lug 22 are equipped with thermoplastic polymer and seal between positive pole ear 21, negative lug 22 and super thin metal shell 10
Layer;Super thin metal shell 10 includes that the surface of super thin metal plate layer 11 is coated with high heat conductive insulating coating;Thermoplastic polymer is close
Sealing includes that positive pole ear heat melts sealant 31 and negative lug heat melts sealant 32, and it includes just that positive pole ear heat, which melts sealant 31,
The adhesive layer of pole tab and thermoplastic polymer, the adhesive layer of thermoplastic polymer and super thin metal shell, positive pole ear and super
The hot melt fused layer of thin metal shell;Negative lug heat melts the bonding that sealant 32 includes negative lug and thermoplastic polymer
Layer, the adhesive layer of thermoplastic polymer and super thin metal shell, negative lug and super thin metal shell hot melt fused layer.
Novel lithium battery with super thin metal shell of the invention, has the advantage that
It 1, can be by the thickness reduction of naked battery core shell to the limit, so that the volume energy density of power battery is higher;It is excellent
Select it is low, super thin metal shell with a thickness of 0.02-0.2mm;It is highly preferred that super thin metal shell with a thickness of 0.05-0.15mm;
2, the super thin metal plate layer of super thin metal shell using stainless steel, perhaps lead by aluminium alloy stainless steel or aluminium itself
Hot property is better than aluminum-plastic composite membrane or steel plastic compount film, and stainless steel surface sprays high heat conductive insulating composite coating in addition, such as adopts
With graphene heat conducting film, battery core plane thermal conductivity performance superelevation, heat is directly conducted to bottom water-cooled plate or radiator, can cancel
Aluminum heat conducting plate in Soft Roll mould group between battery core, further increases the energy density of power battery pack;
3. realizing the encapsulation of ultra-thin logging, package strength and resistance to electricity using the technology mode of pre- punching hole bag making, heat-sealing, welding
Solution liquid corrosion resistance is significantly better than using aluminum-plastic composite membrane;
4. raw material cost is low, promoted for the energy density that current driving force battery faces, battery heat dissipation and cost are dropped
It is close can to take into account energy by using this unconventional battery housing material of super thin metal shell for low three Important Problems
The promotion of degree and battery heat dissipation performance, at the same the cost of housing material and existing housing material structure also have it is certain
Advantage.
In the present embodiment, high heat conductive insulating coating includes high thermal conductivity coating 12 and electronic isolation coating 13, high thermal conductivity coating
12 be graphite-like heat conducting film or heat conductive silica gel class heat conducting film, and electronic isolation coating 13 is that resistivity is greater than 1010Ω m's is inorganic
Object or polymer;Being also possible to high heat conductive insulating coating is high heat conductive insulating composite coating, and high heat conductive insulating composite coating is
Outer surface is covered with the graphite heat conducting composite membrane or graphene heat conduction composite membrane of PET.
It is preferred that low, super thin metal plate layer 11 uses stainless steel or aluminium alloy, and stainless steel is austenitic stainless steel, ferrite
The double item stainless steels of type stainless steel or austenite ferrite, aluminium alloy be 1 be fine aluminium, 1 line aluminium alloy, 3 be alumal, 5 be aluminium
Magnesium alloy, 6 are alusil alloy.
In the present embodiment, pass through welding between super thin metal shell at the non-positive pole ear of naked battery core 20, negative lug
It encapsulates, laser penetration welding, electromagnetism welding or ultrasonic bonding can be used in welding.
In the present embodiment, thermoplastic polymer sealant includes at least one of PP, CPP, is combined together by extruder
Extrusion is prepared.
Preferably, super thin metal shell sheet material is first subjected to pre- punching hole according to battery core design size, prevents thermoplasticity from polymerizeing
There is excessive glue in heat-sealing in object.
By adopting the above technical scheme, this has the novel lithium battery manufacturing process of super thin metal shell as follows:
The preparation of naked battery core: anode pole piece, isolation film, cathode pole piece are laminated in the way of Z-shaped lamination, make every
It is between positive and negative anodes pole piece from film and plays buffer action, with one circle of isolation film package and by gummed paper stickup fixation after the completion of stacking
Obtain naked battery core;
The preparation of super thin metal shell: the side for using Multi-step forming to stretch the super thin metal shell sheet material of 0.1mm thickness
Formula formation pre-set dimension rushes hole, using the structure in double holes, and the airbags hole small in air-cuff placement pre- punching two simultaneously, in addition
The heat-sealing that step is convenient for subsequent tab position is also rushed in advance at the position of cell polar ear;
Battery core encapsulation: the naked battery core prepared is placed in the pre- punching hole of above-mentioned super thin metal shell, is carried out to folded package
And clamp, using laser welding by the non-tab of housing material while and non-tab position when tab weld, pole
Ear position using seal by the way of by thermoplastic polymer pp material heat of the pre-production on tab melt and with outside super thin metal
Shell and tab are bonded together, while upper and lower super thin metal shell is formed electronic isolation with tab and is separated.
Airbag welding and vacuum liquid filling: airbag equally uses laser welding by most of position close to the edge of battery core main body
Welding leaves an osculum and is used as electrolyte filling and chemical conversion final vacuum, vacuum liquid filling is then carried out in drying shed, is infused
(vacuum degree -50KPa) is stood by vacuum after liquid, welding then is fully sealed with laser welding in the outer ledge of airbag;
Hot pressing chemical conversion removes airbag: hot pressing battery formation clamp in battery core being carried out hot pressing chemical conversion, is melted into 80 DEG C of temperature, pressure
900Kgf;In carrying out laser point envelope to reserved liquid injection port on fixture after being melted into, formation gas is obstructed in airbag completely,
Shaping is carried out to battery using cold-hot pressure fixture later, and smart envelope is carried out to airbag side;Finally, directly airbag is cut with cutter
It removes, obtains the battery after chemical conversion.
Battery surface pastes high heat conductive insulating composite membrane: after the completion of battery performance test, carrying out stone to its surface of battery
The package of black alkene heat conducting film is pasted.The graphene heat conducting film is multilayer complex films, is divided into adhesive layer with battery contact portion, followed by
Graphene heat-conducting layer, outer layer are PET insulating film;Battery after being also possible to chemical conversion is after the completion of all electric performance tests, at it
Surface sprays the high-thermal-conductivity epoxy resin that a layer thickness is 0.005mm.Battery outer layer adds the high heat conductive insulating composite membrane or height
After heat-conduction epoxy resin, battery has good heat dissipation effect, can cancel leading between battery core when battery modules assemble
Heating rate plate saves thermal component the space occupied.
The foregoing is merely a prefered embodiment of the invention, cannot limit interest field of the invention, therefore Yi Benfa according to this
Equivalent variations made by bright the scope of the patents still falls within the range that the present invention is covered.