CN211789268U - Multifunctional composite positive plate for chargeable and dischargeable solid battery and secondary battery - Google Patents

Abstract

The utility model discloses a multifunctional composite positive plate for a chargeable and dischargeable solid battery and a secondary battery, the multifunctional composite positive plate comprises a positive current collector layer, an ion conduction electronic insulating layer and a positive active material layer positioned between the positive current collector layer and the ion conduction electronic insulating layer, wherein the positive active material layer is composed of a plurality of positive active material components, and a plurality of positive active material components are distributed in a two-dimensional laminated structure or a three-dimensional stacked structure, so that different functions of different positive active material components are fully exerted, the comprehensive performance of the battery is considered, meanwhile, the ion conduction electronic insulating layer can simultaneously conduct ions and block the transport of electrons, so that the introduction of liquid electrolyte and internal short-circuit self-discharge are avoided, the safety of the battery is improved, and the multifunctional composite positive plate and the secondary battery which have comprehensive excellent performances such as safety, multiplying power characteristics, high and low temperature characteristics, service life, cycle life and the like are obtained.

Description

Multifunctional composite positive plate for chargeable and dischargeable solid battery and secondary battery

Technical Field

The utility model belongs to electrochemistry energy storage device and new forms of energy material field relate to a can fill multi-functional composite anode plate and secondary battery for solid state battery.

Background

The traditional lithium ion battery positive plate mainly comprises a positive current collector layer and a single positive active material layer 2, wherein the current collector mainly realizes the functions of structural support and electronic drainage, the positive active material layer is mainly of a porous structure, the positive active material layer is a porous structure pole piece consisting of granular positive active materials, granular or linear electronic conductive additives and a binder, the ion transmission function can not be realized under the dry electrode sheet state or the condition that no electrolyte is injected and infiltrated, electrons can only be conducted, and the battery can not normally work, so that the traditional lithium ion battery pole piece can not be directly applied to a solid-state battery.

In addition, the traditional secondary battery, such as a lithium ion battery, has a flowable organic liquid electrolyte inside, and a positive plate, a diaphragm, a negative plate and a liquid electrolyte in the lithium ion battery are all components with single independent driving function, which cannot be fused or replaced with each other, and the organic liquid electrolyte has flammability and potential safety hazard, and the link of injecting the organic liquid electrolyte has harsh requirements on the environment, so the safety of the battery is improved; it is necessary to reduce the amount of liquid electrolyte or to use no flammable liquid electrolyte, and if the amount of liquid electrolyte is reduced, the performance of the battery is affected, and the battery basically cannot work normally without adding liquid electrolyte.

Therefore, in order to satisfy the requirement of normal operation of the battery and solve the safety of the battery, the development of a safe and reliable positive electrode sheet suitable for the solid-state battery is required.

SUMMERY OF THE UTILITY MODEL

In order to overcome the above problems, the present inventors have conducted intensive studies and designed a multifunctional composite positive plate for a rechargeable solid battery, comprising a positive current collector layer, an ion conducting electronic insulating layer, and a positive active material layer disposed between the positive current collector layer and the ion conducting electronic insulating layer, wherein the positive active material layer is composed of a plurality of positive active material components, and the plurality of positive active material components are distributed in a two-dimensional stacked structure or a three-dimensional stacked structure, thereby fully playing different functions of different positive active material components, and taking into account the comprehensive performance of the battery, and the ion conducting electronic insulating layer can simultaneously conduct ions and block the transport of electrons, thereby avoiding the introduction of liquid electrolyte and the internal short-circuit self-discharge, improving the safety of the battery, and obtaining the multifunctional composite positive plate and the secondary battery which take into account the comprehensive excellent performances such as safety, rate characteristic, high and low temperature characteristic, service life, cycle life, etc., thereby completing the utility model.

An object of the utility model is to provide a can fill solid-state battery with multi-functional compound positive plate, multi-functional compound positive plate includes anodal current collector layer and ion conduction electron insulating layer and is located anodal active material layer between anodal current collector layer and the ion conduction electron insulating layer.

The positive electrode active material layer and the ion conduction electronic insulating layer are distributed in a two-dimensional or three-dimensional stacking structure,

the three-dimensional stacking structure is distributed in a three-dimensional regular or irregular distribution,

preferably, the three-dimensional stacking structure distribution comprises an equal spacing structure distribution or a tooth array structure distribution.

The positive electrode active material layer includes a plurality of positive electrode active material components made of a positive electrode material, a binder, an electron conductive additive, and an ion conductive additive.

The plurality of positive electrode active material assemblies are distributed in a two-dimensional layered structure.

The plurality of positive active material assemblies are distributed in a three-dimensional stacked structure.

The tooth array structure distribution is at least one of rectangular tooth array distribution, triangular tooth array distribution or trapezoidal tooth array distribution.

The tooth array structure is distributed in a rectangular tooth array type distribution, a triangular tooth array type distribution or a trapezoidal tooth array type distribution.

The positive electrode materials in the plurality of positive electrode active material assemblies are different.

The positive electrode materials in the plurality of positive electrode active material assemblies are the same, and the concentrations of the positive electrode materials are different.

The plurality of positive electrode active material assemblies are distributed in a gradient structure.

The utility model provides a secondary battery, this secondary battery contain the utility model discloses the first aspect multi-functional compound positive plate.

The utility model discloses the beneficial effect who has does:

(1) the utility model provides a positive active material layer of a multifunctional composite positive plate, which comprises a plurality of positive active material components, wherein the physical properties or the chemical compositions of the positive active material components are different, thereby enhancing the functions of the positive plate;

(2) the utility model discloses a design a plurality of anodal active material subassemblies and pile the distribution mode for two-dimentional stratiform or three-dimensional stack structural design, overcome the functional defect of single component, increase the area of contact between the anodal active material subassembly simultaneously, strengthen the adhesion, increased different active material subassemblies and with the ion conducting material between the area of contact, make the secondary battery who prepares have excellent multiplying power characteristic, long cycle life, energy density advantage such as high;

(3) the utility model designs the ion conduction electronic insulating layer, so that the multifunctional composite positive plate can form a continuous ion transmission network in the pole piece under the dry electrode state, and the solid secondary battery prepared by using the composite positive plate can avoid the introduction of liquid electrolyte and the self-discharge of internal resistance circuit, thereby improving the safety of the secondary battery;

(4) the utility model provides a multi-functional composite positive plate and contain its secondary battery has overcome current positive plate anodal active material layer component singleness, and the defect of function singleness, and removes the introduction of liquid electrolyte from, has obtained multi-functional composite positive plate and secondary battery that the comprehensive properties is excellent, if have power density height, energy density height, low temperature discharge rate can be good, high temperature cycle life is long, advantage such as security height, be suitable for extensive popularization.

Drawings

Fig. 1 shows a schematic view of the operating principle of a secondary battery;

fig. 2 shows a schematic view of a secondary battery structure;

fig. 3 shows a schematic view of the structure of the positive electrode sheet of comparative example 1;

fig. 4 is a schematic view showing the structure of the multifunctional composite positive electrode sheet of example 1;

fig. 5 is a schematic view showing the structure of the multifunctional composite positive electrode sheet of example 2;

fig. 6 shows a schematic structural view of the multifunctional composite positive electrode sheet of example 3;

fig. 7 shows a schematic structural view of the multifunctional composite positive electrode sheet of example 4;

fig. 8 is a schematic view showing the structure of the multifunctional composite positive electrode sheet of example 5;

FIG. 9 is a graph showing the comparison of the discharge specific capacity test results of the multifunctional composite positive electrode sheet of example 1 and the positive electrode sheet of comparative example 1;

fig. 10 is a graph showing the comparison of the results of the rate and cyclicity tests of the multifunctional composite positive electrode sheet of example 1 and the positive electrode sheet of comparative example 1;

fig. 11 shows an SEM image of the multifunctional composite positive electrode sheet obtained in example 1.

The reference numbers illustrate:

100-positive plate;

101-positive current collector layer;

102-positive electrode active material layer;

1021-a first positive active material assembly;

1022 — a second positive active material component;

102' -rectangular teeth;

103' -inverted rectangular teeth;

103-an ionically conducting electronically insulating layer;

200-a membrane;

300-negative pole piece;

301-negative current collector layer;

302-negative electrode active material layer.

Detailed Description

The invention is explained in more detail below with reference to the drawings and preferred embodiments. The features and advantages of the present invention will become more apparent from the description.

As shown in fig. 1, which is a basic operation diagram of a lithium ion secondary battery, during charging, lithium ions reach the particle surface from the inside of positive electrode material particles in a positive electrode sheet active material layer in a diffusion manner, and then reach the surface of negative electrode material particles in a negative electrode sheet active material layer after passing through a porous diaphragm through surface migration and liquid electrolyte transportation, and meanwhile, electrons are transported to the surface of the negative electrode particles from the positive electrode material particles through a positive electrode current collector aluminum foil and an external circuit, and are diffused into the inside of the negative electrode material particles after being compounded with the lithium ions migrated from the positive electrode, thereby completing a charging process; the discharge process is reversed.

In the working principle of the battery, the positive current collector and the negative current collector respectively play roles in supporting an electrode active substance layer and conducting electrons, when the battery is charged, the positive active substance layer provides lithium ions, the liquid electrolyte plays a role in transporting ions in the battery, the diaphragm plays a role in isolating a positive plate from a negative plate, and the negative active substance layer is mainly used for storing electrons and ions from the positive electrode.

Fig. 2 shows a schematic diagram of a basic structure of a secondary battery, which mainly includes four major parts, a positive electrode sheet 100, a separator 200, a negative electrode sheet 300, and a liquid electrolyte soaked therein. The positive electrode sheet 100 is composed of a positive electrode current collector layer 101 and a positive electrode active material layer 102, as shown in fig. 3, the positive electrode sheet 100 is schematically shown in the structure, the separator 200 is composed of an organic polymer material, the negative electrode sheet 300 is composed of a negative electrode current collector layer 301 and a negative electrode active material layer 302, and the liquid electrolyte is injected into the secondary battery in a dry inert atmosphere by negative pressure.

According to the utility model discloses, a can fill and discharge solid-state battery with multi-functional compound positive plate is provided, this multi-functional compound positive plate includes anodal current collector layer 101 and ion conduction electron insulating layer 103 and is located anodal active material layer 102 between anodal current collector layer 101 and the ion conduction electron insulating layer 103.

The utility model discloses in, the effect of the main realization structural support of positive current collector layer and electron drainage, energy storage and transfer are mainly realized to positive active material layer (electron ion mixed conducting layer), the ion switches on the electron insulating layer and is used for switching on the ion, realize that the ion transports in the battery is inside, electronic insulation can ensure that the battery can not the short circuit simultaneously, this positive plate is arranged in solid-state battery, can realize ion and electron transmission's function simultaneously under the dry electrode state, need not pour into liquid electrolyte into, can show the security that improves the battery.

The utility model discloses a multi-functional compound positive plate is applicable to but not limited to lithium ion, sodium ion, potassium ion, magnesium ion, aluminium ion etc. based on solid electrolyte's solid secondary battery.

According to the present invention, the base material of the positive electrode current collector layer 101 is an oxidation-resistant metal foil or alloy, preferably at least one of an aluminum foil, a nickel foil, a titanium foil, an iron foil, an alloy thereof, and the like.

According to the utility model discloses, the thickness of positive current collector layer 101 substrate is 8 ~ 25 μm, preferably 10 ~ 20 μm, more preferably 16 μm.

According to the utility model discloses, the thickness sum of anodal active material layer and ion conduction electron insulating layer is 40 ~ 250 μm, preferably 50 ~ 200 μm, more preferably 80 ~ 150 μm.

According to the utility model discloses, ion conduction electron insulating layer 103 includes ion conducting material, ion conducting material can form the ion conducting network, and preferred ion conducting material is applicable in at least one kind in the material of lithium ion, sodium ion, potassium ion, magnesium ion, aluminium ion solid electrolyte, more preferably, ion conducting material comprises through physics or chemical bond effect at least one kind in polyethylene oxide, polymethyl methacrylate, polyvinylidene fluoride, polytetrafluoroethylene, titanium aluminium lithium phosphate, lithium lanthanum zirconium oxygen compound, lithium germanium phosphorus sulphur, lithium phosphorus nitrogen oxygen, lithium lanthanum titanium oxygen, lithium hexafluorophosphate, lithium tetrafluoroborate, two trifluoromethyl sulfonyl imide lithium, polypropylene carbonate, polyethylene carbonate etc..

The inventor finds that the active material layer of the existing positive plate has single component and can not meet various requirements in the practical use of the battery, such as the requirements of comprehensive indexes of power density, energy density, low-temperature discharge rate, high-temperature cycle life, safety and the like. For example, lithium iron phosphate's cycle life is longer, but the rate performance is than poor, and the rate characteristic of lithium manganate is better, the utility model discloses the discovery, with the compound anodal active material layer of preparation of lithium iron phosphate and lithium manganate, can effectively solve the battery rate problem of discharging, can compromise the long cycle life requirement of battery simultaneously.

According to the present invention, the positive electrode active material layer 102 includes a plurality of (two or more) positive electrode active material members, and the physical properties or chemical compositions of the plurality of positive electrode active material members are different.

According to the utility model discloses, anodal active material subassembly is made by cathode material, binder, electron conductive additive and ion conductive additive, and preferably, a plurality of anodal active material subassemblies link together through physical contact or chemical bond mode of action.

According to the utility model discloses, among the positive pole active material subassembly, the mass fraction (concentration) of positive pole material is 50% -99.6%, and the binder is 0.2% -20%, and electron conductive additive 0.2% -15%, ion conductive additive are 0.05% -40%, and the mass fraction sum of positive pole material, binder, electron conductive additive and ion conductive additive is 100%.

According to the utility model discloses preferred embodiment, the cathode material is at least one kind in the cathode material that can be used to lithium ion, sodium ion, potassium ion, magnesium ion, aluminium ion secondary battery, preferably, the cathode material is selected from lithium cobaltate, nickel cobalt lithium manganate, nickel cobalt lithium aluminate, lithium manganate, lithium iron phosphate, lithium iron manganese phosphate, lithium nickel manganese phosphate, at least one kind in sodium iron copper manganese oxide, sodium manganese oxide, prussian blue, sodium vanadium phosphate, titanium sodium phosphate etc. preferably selected from one or several kinds in lithium iron phosphate, lithium cobaltate, lithium nickel manganese oxide, nickel cobalt lithium manganese oxide.

According to a preferred embodiment of the present invention, the positive electrode active material assembly in the plurality of positive electrode active material layers 102 is distributed between the positive electrode current collector layer 101 and the ion conducting electron insulating layer 103 in a two-dimensional laminated structure.

According to another preferred embodiment of the present invention, the positive electrode active material assembly in the plurality of positive electrode active material layers 102 is distributed between the positive electrode current collector layer 101 and the ion conducting electronic insulating layer 103 in a three-dimensional stacked structure.

According to a preferred embodiment of the present invention, when the plurality of positive electrode active material assemblies are distributed in a two-dimensional stacked structure or a three-dimensional stacked structure, the types of the positive electrode materials in the plurality of positive electrode active material assemblies are the same, and the mass fractions (concentrations) of the positive electrode materials are different.

According to another preferred embodiment of the present invention, when the plurality of positive electrode active material assemblies are distributed in a two-dimensional stacked structure or a three-dimensional stacked structure, the types of the positive electrode materials in the plurality of positive electrode active material assemblies are different, and the concentrations of the positive electrode materials are preferably the same.

According to the present invention, when the plurality of positive electrode active material assemblies are distributed in the two-dimensional stacked structure, the positive electrode materials in the plurality of positive electrode active material assemblies are the same, and the plurality of positive electrode active material assemblies are distributed in the gradient structure, preferably, the concentration of the positive electrode materials in the plurality of positive electrode active material assemblies is changed in a gradient manner, and more preferably, in the direction from the positive electrode current collector layer to the separator, the plurality of positive electrode active material assemblies are gradually decreased or gradually decreased from high to low according to the mass fraction (concentration) of the positive electrode materials contained therein.

According to a preferred embodiment of the present invention, in the positive electrode active material layer, different positive electrode active material assemblies may be combined in a two-dimensional layered distribution manner, and preferably, the positive electrode active material assemblies are combined in a stacked manner, and the thickness of each positive electrode active material assembly is uniform, for example, two-dimensional double-layer lamination combination, two-dimensional multilayer lamination combination.

According to the preferred embodiment of the present invention, the positive electrode active material layer has different types of positive electrode materials in different positive electrode active material assemblies, and the different positive electrode active material assemblies in the positive electrode active material layer can be distributed in a two-dimensional stacked structure or a three-dimensional stacked structure.

According to the present invention, in the positive electrode active material layer, different positive electrode active material assemblies containing different kinds of positive electrode materials are distributed in two-dimensional layers, that is, different two-dimensional stacked active material assemblies are stacked on the positive electrode current collector layer, such as two-dimensional stacked layers and two-dimensional stacked layers, preferably, the thickness of each positive electrode active material assembly is uniform, more preferably, the thickness of each positive electrode active material assembly is the same or different, and the thickness of each positive electrode active material assembly is designed according to actual needs.

According to another preferred embodiment of the present invention, in the positive electrode active material layer, a plurality of positive electrode active material members containing different kinds of positive electrode materials are combined in a three-dimensional stacking manner, and the three-dimensional stacking manner is a three-dimensional regular structure or a three-dimensional irregular structure.

According to the preferred embodiment of the present invention, the plurality (e.g. two) of positive active material assemblies are distributed in a three-dimensional prong structure or in an equally spaced structure, and the three-dimensional prong structure is preferably distributed in a tooth array structure.

According to the preferred embodiment of the present invention, the plurality of positive electrode active material assemblies are alternately distributed or distributed in an equi-spaced structure on the positive electrode current collector layer, that is, the plurality of positive electrode active material assemblies are alternately contacted with the positive electrode current collector layer, respectively, and the equi-spaced distribution is, for example, equi-spaced rectangular distribution, equi-spaced trapezoidal distribution or equi-spaced triangular distribution. Wherein, rectangle, trapezoid, triangle are the cross section shape of positive electrode active material subassembly.

According to the utility model relates to a preferred embodiment, different positive pole active material subassemblies are profile of tooth array structure and distribute to make the active material layer area of contact between two kinds of positive pole active material subassemblies increase, strengthen the cohesive force between different positive pole active material subassemblies, simultaneously, also can enlarge the area of contact of positive pole active material and ion conducting material, promote the electrochemical properties of positive electrode material, and then improve the multiplying power characteristic of battery.

According to the preferred embodiment of the present invention, the three-dimensional tine structure distribution (tooth array structure distribution) is preferably one or more of a rectangular tooth array type, a triangular tooth array type, a trapezoidal tooth array type, and the like.

According to the preferred embodiment of the present invention, the binder is an organic polymer material that can be used as a binder for a positive electrode material of a secondary battery, and preferably, the binder is one or more selected from polyvinylidene fluoride, polytetrafluoroethylene, polymethyl acrylate, and the like.

According to a preferred embodiment of the present invention, the electronic conductive additive is a carbon material, preferably at least one selected from carbon black, carbon nanotube, graphene, acetylene black, and the like.

According to the utility model, the ion conductive additive is selected from one or more of bis (trifluoromethyl) sulfonyl imide lithium, nano titanium aluminum lithium phosphate and polyethylene oxide.

According to the utility model discloses, the preparation process of positive active material layer: the positive electrode material, the electronic conductive additive, the binder and the ionic conductive additive are prepared into slurry, and the slurry is coated on the positive electrode current collector layer and dried.

According to a preferred embodiment of the present invention, the positive electrode current collector layer 101, the positive electrode active material layer 102, and the ion conducting insulating layer 103 are sequentially stacked in a two-dimensional stacked structure distribution.

According to a preferred embodiment of the present invention, the positive electrode active material layer 102 and the ion conducting electronic insulating layer 103 may be distributed through a two-dimensional or three-dimensional stacking structure, and preferably, the positive electrode active material layer 102 and the ion conducting electronic insulating layer 103 are distributed in a three-dimensional fork tooth structure, and the three-dimensional fork tooth structure is preferably distributed in a tooth shape array structure, and more preferably distributed in at least one of a rectangular tooth array type, a triangular tooth array type or a trapezoidal tooth array type.

According to the utility model discloses, when distributing for profile of tooth array structure, positive profile of tooth and the combination of pawl shape contact surface have increased anodal active substance layer and the area of contact that the ion switched on electronic insulation to increased the transmission efficiency of ion, and then improved the multiplying power performance, the cyclicity ability etc. of battery.

According to the preferred embodiment of the present invention, the multifunctional composite positive plate is prepared by spraying the positive active material layer 102 and the ion conducting electronic insulating layer 103, coating by extrusion at equal intervals, sputtering or rolling with a mask structure, casting, pulsed laser deposition, chemical vapor deposition, atomic layer deposition, 3D printing, etc. on the positive current collector layer 101.

The utility model provides a can fill and fill multi-functional composite positive plate for solid-state battery can realize the ion transmission network under the dry electrode state, need not to introduce liquid electrolyte.

The utility model discloses a multi-functional compound positive plate is prepared by following method, and this method includes: sequentially forming a positive electrode active material layer and an ion conduction electron insulating layer on the positive electrode current collector layer,

preferably, the positive electrode active material layer and the ion conducting electronic insulation layer are formed by one or more of spraying, equal-interval extrusion coating, sputtering with a mask structure, rolling, casting, pulsed laser deposition, chemical vapor deposition, atomic layer deposition, 3D printing and the like,

more preferably, the positive electrode active material layer is first prepared on the positive electrode current collector layer, and then the ion conducting electron insulating layer is prepared on the positive electrode active material layer in at least one of spraying, extrusion coating, sputtering with a mask structure, rolling, casting, pulsed laser deposition, chemical vapor deposition, atomic layer deposition, and 3D printing.

According to a preferred embodiment of the present invention, the positive electrode active material layer is formed by the positive electrode active material assembly by one or more of spraying, extrusion coating (e.g., extrusion coating at equal intervals), sputtering with a mask structure (mask sputtering), rolling, pulsed laser deposition, chemical vapor deposition, atomic layer deposition, electrochemical deposition, 3D printing, and the like.

According to the utility model relates to a preferred embodiment, multi-functional composite positive plate's preparation process: mixing a positive electrode active material, an electronic conductive additive, an ionic conductive additive and a binder to prepare slurry, coating the slurry on a positive electrode current collector layer, and drying to obtain a pole piece formed by a first active material component and the positive electrode current collector layer, preferably forming other active material components on the pole piece according to the structural design of the positive electrode active material component to obtain a positive electrode active material layer; then forming an ion conduction electronic insulating layer on the positive active material layer to obtain a multifunctional composite positive plate;

preferably, the positive electrode active material, the electronic conductive additive, the ionic conductive additive and the binder are weighed according to the mass ratio, are gradually added into a solvent (such as NMP), the solid content is controlled to be 40% -60%, and are uniformly stirred to obtain a mixed slurry, the mixed slurry is coated on the positive electrode current collector layer, other active material components are formed according to the structural design of the positive electrode active material layer, and then the ionic conduction electronic insulating layer is prepared on the positive electrode active material layer to obtain the multifunctional composite positive electrode sheet, for example, the positive electrode active material layer and the ionic conduction electronic insulating layer with a two-dimensional laminated structure or an equal-interval (rectangular) distribution structure can be obtained through spraying, equal-interval extrusion coating, rolling and the like.

According to the utility model discloses another preferred embodiment, multi-functional composite positive plate's preparation process: the positive electrode active material, the electron conductive additive, the ion conductive additive and the binder are mixed according to the mass ratio to form a dry powder mixture, the dry powder mixture is deposited on a positive electrode current collector layer (or other positive electrode active material components), a first positive electrode active material component is formed, according to the structural design of the positive electrode active material layer, similarly, other positive electrode active material components are formed on the first positive electrode active material component, and then a pole piece formed by the positive electrode active material layer and the positive electrode current collector layer is obtained, according to the structural design of the positive electrode active material layer and the ion conduction electron insulation layer, the ion conduction electron insulation layer is formed on the pole piece, and the multifunctional composite positive pole piece is obtained. For example, the tooth array structure can be obtained by space coating, sputtering with a mask structure, rolling, pulsed laser deposition, chemical vapor deposition, atomic layer deposition, electrochemical deposition, 3D printing, and the like.

The utility model provides a multi-functional compound positive plate can be used to the preparation and can fill and discharge solid-state battery, secondary battery.

The utility model provides a secondary battery who contains multi-functional compound positive plate, this secondary battery include multi-functional compound positive plate, diaphragm and negative pole piece, positive plate, diaphragm and negative pole piece are in the same place through physics or chemical mode combination such as coiling, stromatolite, pack into among the packaging material, make through modes such as high temperature hot pressing, cold isostatic pressing secondary battery, preferably, diaphragm and negative pole piece are ion conduction membrane and take mass flow body bearing structure's metal lithium and alloy piece, more preferably, need not the diaphragm, and the negative pole piece is for taking mass flow body bearing structure's metal lithium and alloy piece.

According to the utility model discloses, secondary battery including multi-functional composite positive plate has excellent high temperature cycle performance, rate capability and capacity performance ability, for example, compares with conventional secondary battery, high temperature 55 ℃/50^thThe circulation retention rate is improved from 97.8 percent to 99 percent, and the 1C/0.1C ratio is improved from 89.8 percent to 91.5 percent; the diaphragm-free secondary battery prepared by the multifunctional composite positive plate has the discharge specific capacity of 0.1C and 1C reaching 126mAh/g and 100mAh/g under the test condition of 85 ℃, the 1C/0.1C ratio reaching 79 percent, which is much higher than 33 percent of that of the conventional positive plate under the condition of not injecting electrolyte.

The utility model provides a multi-functional composite positive plate, structure through to anodal active material layer designs, the design is two-dimentional laminated structure or three-dimensional stack structure, it is single to have overcome current anodal active material layer structure component, the shortcoming of function singleness, it is not enough to have improved design among the traditional secondary battery, multi-functional composite positive plate and secondary battery that the comprehensive properties is excellent have been obtained, if have power density height, energy density is high, low temperature discharge rate performance is good, the high temperature cycle is longe-lived, high security, be suitable for extensive popularization, and simultaneously, design ion conduction electronic insulation layer in multi-functional composite positive plate, the introduction of liquid electrolyte has been avoided, can be used to prepare secondary solid battery, the realization is under the dry electrode state, carry out the function of ion conduction, the security of the secondary battery who prepares is improved.

Examples

Example 1

As shown in fig. 4, a multifunctional composite positive plate for a rechargeable solid battery includes a positive current collector layer, a positive active material layer, and an ion conductive electronic insulating layer, which are distributed in a two-dimensional stacked structure, wherein the base material of the positive current collector layer 101 is an aluminum foil, the mass fraction of nickel-cobalt lithium manganate in the positive active material layer 102 is 80%, the binder is polyvinylidene fluoride, the mass fraction is 9%, the electronic conductive additive is carbon black, the mass fraction is 3%, the ion conductive additive is bis (trifluoromethyl) sulfimide lithium and nano titanium aluminum lithium phosphate, the mass fractions are 4%, the ion conductive electronic insulating layer 103 is a compound of nano titanium aluminum lithium phosphate and polyvinylidene fluoride, the mass fraction of titanium aluminum lithium phosphate is 95%, and the mass fraction of polyvinylidene fluoride is 5%.

The preparation process of the multifunctional composite positive plate for the chargeable and dischargeable solid battery comprises the following steps:

(1) mixing nickel cobalt lithium manganate, polyvinylidene fluoride, carbon black, lithium bistrifluoromethylsulfonyl imide and nano lithium titanium aluminum phosphate according to a ratio of 80: 9: 3: 4: 4, gradually adding the mixture into an NMP solvent, controlling the solid content to be 50%, uniformly stirring to obtain slurry, uniformly and continuously coating the slurry on an aluminum foil by using an automatic coating machine, and drying for later use to obtain a pole piece;

(2) nano lithium aluminum titanium phosphate and polyvinylidene fluoride are mixed according to the weight ratio of 95: and 5, weighing the components in percentage by mass, gradually adding the components into an NMP solvent, controlling the solid content to be 50%, uniformly stirring, uniformly and continuously coating the slurry on the upper layer of the pole piece in the step (1) by using an automatic coating machine, and drying to obtain the multifunctional composite positive pole piece.

The obtained multifunctional composite positive electrode sheet was subjected to SEM test, and the obtained SEM image of the longitudinal section is shown in fig. 11, and as can be seen from fig. 11, the multifunctional composite positive electrode sheet having a two-dimensional lamination structure was obtained in example 1, and the lamination structure of the composite positive electrode sheet, a-positive electrode current collector layer, b-positive electrode active material layer, and c-positive electrode ion conduction electron insulating layer, can be clearly seen.

Example 2

As shown in fig. 5, the multifunctional composite positive plate for the rechargeable solid battery comprises a positive current collector layer 101, a positive active material layer 102 and an ion conduction electronic insulation layer 103, wherein the positive current collector layer is distributed in a two-dimensional stacked structure, the substrate of the positive current collector layer is an aluminum foil, and the positive active material layer comprises 2 positive active material components, namely a first positive active material component 1021 and a second positive active material component 1022.

The positive electrode material of the first positive electrode active material component 1021 is lithium nickel cobalt manganese oxide, the mass fraction of the positive electrode material is 90%, the binder is polyvinylidene fluoride, the mass fraction of the binder is 4%, the electronic conductive additive is carbon black, the mass fraction of the electronic conductive additive is 2%, the ionic conductive additive is lithium bis (trifluoromethyl) sulfonyl imide and nano lithium titanium aluminum phosphate, and the mass fractions of the ionic conductive additive and the nano lithium titanium aluminum phosphate are respectively 2%;

the positive electrode material of the second positive electrode active material component 1022 is nickel cobalt lithium manganate with the mass fraction of 80%, the binder is polyvinylidene fluoride with the mass fraction of 9%, the electronic conductive additive is carbon black with the mass fraction of 3%, and the ionic conductive additive is bis (trifluoromethyl) sulfonyl imide lithium and nano titanium aluminum lithium phosphate with the mass fraction of 4% respectively;

the ion conduction electronic insulating layer 103 is a nano titanium aluminum lithium phosphate and polyvinylidene fluoride compound, wherein the mass fraction of the titanium aluminum lithium phosphate is 90%, and the mass fraction of the polyvinylidene fluoride is 10%.

The first active material assembly 1021 and the second active material assembly 1022 are distributed in a two-dimensional stacked structure.

The preparation process of the multifunctional composite positive plate for the chargeable and dischargeable solid battery comprises the following steps:

(1) lithium nickel cobalt manganese oxide, polyvinylidene fluoride, carbon black, lithium bistrifluoromethylsulfonyl imide and nano lithium titanium aluminum phosphate are mixed according to a ratio of 90: 4: 2: 2: 2, gradually adding the mixture into an NMP solvent, controlling the solid content to be 40%, uniformly stirring to obtain slurry, uniformly and continuously coating the slurry on an aluminum foil by using an automatic coating machine, and drying for later use to obtain a pole piece;

(2) lithium nickel cobalt manganese oxide, polyvinylidene fluoride, carbon black, lithium bis (trifluoromethyl) sulfonyl imide and nano lithium titanium aluminum phosphate are mixed according to a ratio of 80: 9: 3: 4: 4, gradually adding the mixture into an NMP solvent, controlling the solid content to be 40%, uniformly stirring to obtain slurry, uniformly and continuously coating the slurry on the upper layer of the pole piece dried in the step (1) by using an automatic coating machine, and drying for later use;

(3) mixing nano lithium aluminum titanium phosphate and polyvinylidene fluoride according to the weight ratio of 90: and (3) weighing 10 mass fractions, gradually adding the weighed materials into an NMP solvent, controlling the solid content to be 50%, uniformly stirring, uniformly and continuously coating the slurry on the upper layer of the pole piece in the step (2) by using an automatic coating machine, and drying to obtain the multifunctional composite positive pole piece.

Example 3

As shown in fig. 6, the multifunctional composite positive plate for the rechargeable solid battery comprises a positive current collector layer 101, a positive active material layer 102 and an ion conduction electronic insulation layer 103, wherein the positive current collector layer 101 is an aluminum foil, the positive active material layer comprises 2 positive active material assemblies, namely a first positive active material assembly 1021 and a second positive active material assembly 1022;

the positive electrode material of the first positive electrode active material component 1021 is nickel cobalt lithium manganate, the mass fraction of the positive electrode material is 85%, the binder is polyvinylidene fluoride, the mass fraction of the binder is 5%, the electronic conductive additive is carbon black, the mass fraction of the electronic conductive additive is 2%, the ionic conductive additive is bis (trifluoromethyl) sulfonyl imide lithium and nano titanium aluminum lithium phosphate, and the mass fractions of the ionic conductive additive and the nano titanium aluminum lithium phosphate are respectively 4%;

the positive electrode material of the second positive electrode active material component 1022 is lithium manganate with a mass fraction of 90%, the binder is polyvinylidene fluoride with a mass fraction of 4%, the electronic conductive additive is carbon black with a mass fraction of 2%, and the ionic conductive additive is bis (trifluoromethyl) sulfimide lithium and nano titanium aluminum lithium phosphate with a mass fraction of 2% respectively;

the ion conduction electron insulation layer 103 is a nano lithium lanthanum titanium oxide and polyvinylidene fluoride compound, wherein the mass fraction of lithium lanthanum titanium oxide is 80%, and the mass fraction of polyvinylidene fluoride is 20%.

The first active material assembly and the second active material assembly are distributed in a two-dimensional stacked structure.

The preparation process of the multifunctional composite positive plate is as follows:

(1) lithium nickel cobalt manganese oxide, polyvinylidene fluoride, carbon black, lithium bistrifluoromethylsulfonyl imide and nano lithium titanium aluminum phosphate are mixed according to a ratio of 85 in a first positive electrode active material component 1021: 5: 2: 4: 4, gradually adding the mixture into an NMP solvent, controlling the solid content to be 40%, uniformly stirring to obtain slurry, uniformly and continuously coating the slurry on an aluminum foil by using an automatic coating machine, and drying for later use to obtain a pole piece;

(2) lithium manganate, polyvinylidene fluoride, carbon black, lithium bistrifluoromethylsulfonyl imide and nano lithium titanium aluminum phosphate are mixed according to a ratio of 90: 4: 2: 2: 2, gradually adding the mixture into an NMP solvent, controlling the solid content to be 40%, uniformly stirring to obtain slurry, uniformly and continuously coating the slurry on the upper layer of the pole piece dried in the step (1) by using an automatic coating machine, and drying for later use;

(3) mixing nano lithium lanthanum titanium oxide and polyvinylidene fluoride according to the weight ratio of 80: and (3) weighing the 20 mass fractions, gradually adding the weighed materials into an NMP solvent, controlling the solid content to be 50%, uniformly stirring, uniformly and continuously coating the slurry on the upper layer of the pole piece in the step (2) by using an automatic coating machine, and drying to obtain the multifunctional composite positive pole piece.

Example 4

As shown in fig. 7, a multifunctional composite positive plate for a rechargeable solid battery includes a positive current collector layer 101, a positive active material layer 102, and an ion conductive electronic insulating layer 103, wherein the base material of the positive current collector layer 101 is aluminum foil, the positive material of the positive active material layer 102 is lithium iron phosphate, the mass fraction of the lithium iron phosphate is 85%, the binder is polyvinylidene fluoride, the mass fraction of the polyvinylidene fluoride is 5%, the electronic conductive additive is carbon black, the mass fraction of the electronic conductive additive is 2%, the ion conductive additive is a composite of lithium bis (trifluoromethyl) sulfonyl imide and polyethylene oxide, the mass fraction of the ion conductive additive is 4%, the ion conductive electronic insulating layer 103 is a composite of lithium bis (trifluoromethyl) sulfonyl imide and polyethylene oxide, the mass fraction of the lithium bis (trifluoromethyl) sulfonyl imide is 45%, and the mass fraction of the polyethylene oxide is 55%.

The contact surface between the positive electrode active material layer 102 and the ion conducting electronic insulating layer 103 is a rectangular tooth array structure, wherein the positive electrode active material layer is distributed in a rectangular tooth array structure, the positive electrode active material layer 102 includes a rectangular tooth structure 102 ', the ion conducting electronic insulating layer is distributed in an inverted rectangular tooth array structure, and the ion conducting electronic insulating layer 103 includes an inverted rectangular tooth structure 103'.

The positive electrode current collector layer 101 and the positive electrode active material layer 102 are distributed in a two-dimensional laminated structure, and as shown in the drawing, the positive electrode active material layer 102 and the ion conducting electronic insulating layer 103 are sequentially provided above the positive electrode current collector layer 101.

The preparation method of the multifunctional composite positive plate comprises the following steps:

(1) lithium iron phosphate, polyvinylidene fluoride, carbon black, lithium bistrifluoromethylsulfonyl imide and polyethylene oxide are mixed according to the weight ratio of 85: 5: 2: 4: 4, weighing and mixing the components in the mass ratio to obtain a mixture, sintering the mixture and the polymer sintering aid by adopting a mask sputtering method to obtain a target material, and sputtering and depositing the mixture in the target material on an aluminum foil for later use according to a rectangular tooth array structure;

(2) lithium bistrifluoromethylsulfonyl imide and polyethylene oxide were mixed according to 45: 55 to obtain a mixture, sintering the mixture and the polymer sintering aid by adopting a mask sputtering method to obtain a target material, and sputtering and depositing the mixture in the target material onto the pole piece in the step (1) according to the rectangular tooth array structure to obtain the multifunctional composite positive pole piece with the rectangular tooth array structure.

Example 5

As shown in fig. 8, the multifunctional composite positive plate for the rechargeable solid battery comprises a positive current collector layer 101, a positive active material layer 102 and an ion conduction electronic insulation layer 103, wherein the positive current collector layer 101 is an aluminum foil in a two-dimensional stacked structure, and the positive active material layer 102 comprises 2 positive active material assemblies, namely a first positive active material assembly 1021 and a second positive active material assembly 1022;

the positive electrode material of the first positive electrode active material component 1021 is lithium nickel cobalt manganese oxide, the mass fraction of the positive electrode material is 85%, the binder is polytetrafluoroethylene, the mass fraction of the binder is 4%, the electronic conductive additive is carbon black, the mass fraction of the electronic conductive additive is 3%, the ionic conductive additive is lithium bis (trifluoromethyl) sulfonyl imide and polyethylene oxide, and the mass fractions of the ionic conductive additive and the lithium nickel cobalt lithium manganese oxide are 4% respectively;

the positive electrode material of the second positive electrode active material component 1022 is lithium manganate with a mass fraction of 85%, the binder is polyvinylidene fluoride with a mass fraction of 5%, the electronic conductive additive is carbon black with a mass fraction of 4%, and the ionic conductive additive is lithium bis (trifluoromethyl) sulfonyl imide and nano lithium titanium aluminum phosphate with a mass fraction of 3% each;

the ion conduction electronic insulating layer 103 is a nano titanium aluminum lithium phosphate and polyvinylidene fluoride compound, wherein the titanium aluminum lithium phosphate accounts for 85% and the polyvinylidene fluoride accounts for 15% by mass.

The contact surfaces of the first positive active material assemblies 1021 and the second positive active material assemblies 1022 are distributed in a rectangular tooth array type, wherein the first positive active material assemblies are distributed in a rectangular tooth array type structure, and the second positive active material assemblies are distributed in an inverted rectangular tooth array type structure.

The positive current collector layer 101 and the first positive active material element 1021 are two-dimensionally stacked, and the ion-conducting electronic insulating layer 103 and the second positive active material element 1022 are two-dimensionally stacked.

The preparation method of the multifunctional composite positive plate comprises the following steps:

(1) according to the first positive electrode active material assembly 1021, lithium nickel cobalt manganese oxide, polytetrafluoroethylene, carbon black, lithium bistrifluoromethylsulfonyl imide, polyethylene oxide were mixed in a ratio of 85: 4: 3: 4: 4, mixing to obtain a mixture, sintering the mixture and the polymer sintering aid by adopting a mask sputtering method to obtain a target material, and sputtering and depositing the mixture in the target material on an aluminum foil according to a rectangular tooth array structure for later use;

(2) according to the second positive electrode active material component 1022, lithium manganate, polyvinylidene fluoride, carbon black, lithium bistrifluoromethylsulfonyl imide, and nano lithium titanium aluminum phosphate are mixed according to a ratio of 85: 5: 4: 3: 3, mixing to obtain a mixture, sintering the mixture and the polymer sintering aid by adopting a mask sputtering method to obtain a target material, and sputtering and depositing the mixture in the target material onto the surface of the substrate (1) according to the rectangular tooth array structure for later use;

(3) mixing nano lithium aluminum titanium phosphate and polyvinylidene fluoride according to the weight ratio of 85: 15, gradually adding the slurry into NMP, controlling the solid content to be 50%, uniformly stirring, uniformly and continuously coating the slurry on the upper layer of the pole piece in the step (2) by using an automatic coating machine, and drying to obtain the multifunctional composite positive pole piece.

Comparative example 1

As shown in fig. 3, the conventional secondary battery positive plate includes a positive current collector layer 101 and a positive active material layer 102, the matrix of the positive current collector layer 101 is an aluminum foil, the positive material of the positive active material layer 102 is nickel cobalt lithium manganate, the mass fraction of the positive active material layer is 80%, the binder is polyvinylidene fluoride, the mass fraction of the binder is 10%, the electronic conductive additive is carbon black, and the mass fraction of the electronic conductive additive is 10%.

The preparation method of the positive plate comprises the following steps:

according to the mass ratio of 80: 10: 10, respectively weighing nickel cobalt lithium manganate, polyvinylidene fluoride and carbon black, gradually adding the nickel cobalt lithium manganate, the polyvinylidene fluoride and the carbon black into an NMP solvent, controlling the solid content to be 50%, uniformly stirring to obtain slurry, uniformly and continuously coating the slurry on an aluminum foil by using an automatic coating machine, and drying to obtain the positive plate.

Examples of the experiments

Experimental example 1

The multifunctional composite positive electrode sheet of example 1 and the positive electrode sheet of comparative example 1 were used as positive electrodes, respectively, secondary batteries were prepared according to the schemes in table 1, and the prepared secondary batteries were subjected to performance tests, the specific battery preparation and test schemes are shown in table 1 below, and the test results are shown in fig. 9 and 10. The preparation and test scheme of example 1-a shows that the multifunctional positive plate of example 1 is used as a positive electrode, the metal lithium plate is used as a negative electrode, and the diaphragm is prepared into the secondary battery by adopting a conventional diaphragm.

As can be seen from the test data in fig. 9 and 10, the conventional secondary battery prepared using the composite positive electrode sheet in example 1 has better cyclability and rate characteristics, compared to comparative example 1, at a high temperature of 55 ℃/50 ℃^thThe circulation retention rate is improved from 97.8 percent to 99 percent, and the 1C/0.1C ratio is improved from 89.8 percent to 91.5 percent.

In addition, compared with the comparative example 1, the diaphragm-free solid-state secondary battery prepared by using the composite positive plate in the example 1 has better cyclability and capacity exertion capability under the condition of no electrolyte injection, and the capacity of the conventional positive plate under the condition of no electrolyte injection is tested at 85 ℃, the 0.1C and 1C specific discharge capacity of the conventional positive plate is only 15mAh/g and 5mAh/g, while the 0.1C and 1C specific discharge capacity of the composite positive plate in the example 1 reaches 126mAh/g and 100mAh/g, the 1C/0.1C ratio of the diaphragm-free electrolyte-free secondary battery prepared by using the composite positive plate in the example 1 reaches 79%, and the 1C/0.1C ratio of the conventional positive plate under the condition of no electrolyte injection is only 33%.

TABLE 1

The present invention has been described in detail with reference to the preferred embodiments and the exemplary embodiments. It should be noted, however, that these specific embodiments are only illustrative explanations of the present invention, and do not set any limit to the scope of the present invention. Without departing from the spirit and scope of the present invention, various modifications, equivalent replacements, or modifications may be made to the technical content and embodiments thereof, which all fall within the scope of the present invention. The protection scope of the present invention is subject to the appended claims.

Claims (8)

1. A multifunctional composite positive plate for a chargeable and dischargeable solid battery is characterized by comprising a positive current collector layer, an ion conduction electronic insulating layer and a positive active material layer positioned between the positive current collector layer and the ion conduction electronic insulating layer,

the positive electrode active material layer and the ion conduction electronic insulating layer are distributed in a two-dimensional or three-dimensional stacking structure,

the three-dimensional stacking structure distribution comprises an equal interval structure distribution or a tooth-shaped array structure distribution.

2. The multifunctional composite positive electrode sheet according to claim 1, wherein the positive electrode active material layer comprises a plurality of positive electrode active material components.

3. The multifunctional composite positive electrode sheet according to claim 2, wherein the plurality of positive electrode active material assemblies are distributed in a two-dimensional layered structure.

4. The multifunctional composite positive electrode sheet according to claim 2, wherein the plurality of positive electrode active material assemblies are distributed in a three-dimensional stacked structure.

5. The multifunctional composite positive electrode sheet according to claim 1, wherein the tooth array structure distribution is at least one of a rectangular tooth array distribution, a triangular tooth array distribution, or a trapezoidal tooth array distribution.

6. The multifunctional composite positive electrode sheet according to claim 1, wherein the tooth array structure distribution is in a rectangular tooth array distribution, a triangular tooth array distribution or a trapezoidal tooth array distribution.

7. The multifunctional composite positive electrode sheet according to claim 2, wherein the plurality of positive electrode active material components are distributed in a gradient structure.

8. A secondary battery comprising the multifunctional composite positive electrode sheet according to any one of claims 1 to 7.

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