CN116936935A

CN116936935A - Electrolyte, solid electrolyte, preparation methods, electrolyte solution, battery and device

Info

Publication number: CN116936935A
Application number: CN202311183558.3A
Authority: CN
Inventors: 吴凯; 靳超; 李白清; 金海族; 钟铭
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-09-14
Filing date: 2023-09-14
Publication date: 2023-10-24

Abstract

The application relates to the technical field of batteries, in particular to an electrolyte, a solid electrolyte, preparation methods, electrolyte, a battery and a device. The electrolyte of the present application comprises a shear thickening material having an average aspect ratio value in the range of 5 to 100. The shear thickening material is used in a battery, is added into electrolyte to form a shear thickening system, can passively respond to external rapid excitation, can rapidly increase the viscosity of the system when encountering external rapid impact, and becomes hard so as to resist the external impact, and rapidly returns to an initial state after the excitation is lost.

Description

Electrolyte, solid electrolyte, preparation methods, electrolyte solution, battery and device

Technical Field

The application relates to the technical field of batteries, in particular to an electrolyte, a solid electrolyte, preparation methods, electrolyte, a battery and a device.

Background

Among safety accidents of batteries, for example, safety accidents of electric vehicles and hybrid vehicles, accidents related to batteries have been found to be 30%. In addition, 60% of the fire accidents caused by the collisions are caused by the batteries. It can be said that the collision safety of the battery has become an important factor affecting the safety performance of the new energy automobile.

The existing method for mainly improving the collision safety performance of the automobile has the problems of overweight protection bags, reduction of the endurance mileage of the automobile, slower response and the like.

Disclosure of Invention

The main object of the present application is to provide an electrolyte aimed at improving the resistance of a battery against external impacts.

To achieve the above object, the present application proposes an electrolyte comprising a shear thickening material having an average aspect ratio ranging from 5 to 100, the shear thickening material comprising a nano-oxide and/or a nano-organic polymer.

The shear thickening material is used in a battery, is added into electrolyte to form a shear thickening system, can passively respond to external rapid excitation, can rapidly increase the viscosity of the system when encountering external rapid impact, and becomes hard so as to resist the external impact, and rapidly returns to an initial state after the excitation is lost. In this way, the battery's resistance to external impacts is improved.

The average aspect ratio of the shear thickening material ranges from 5 to 100.

The average length-diameter ratio is in the range, so that the contact probability of the shear thickening material and the adjacent shear thickening material can be improved in a shear thickening system, the collision of the shear thickening material in the thickening stage is facilitated, the effect of resisting external impact under external excitation is improved, and in the process of improving the collision probability of the shear thickening material in the thickening stage, the transfer of lithium ions among different particles in the thickening stage is improved, and the conductivity of the ions in the thickening stage is improved; in addition, the contact probability among particles in the standing stage of the shear thickening system is facilitated, and the ion transfer is improved.

Shear thickening materials in the present application include, but are not limited to, nano-oxides and/or nano-organic polymers.

Nano-oxides refer to oxides having particle sizes up to the nano-scale. The nano oxide has small size and large specific surface area, and is easy to modify. The nano-oxide helps to form a shear thickening system in the solvent.

Nano-organic polymers refer to nano-sized organic polymers that aid in the formation of a shear thickening system in a solvent.

Optionally, the average aspect ratio of the shear thickening material ranges from 20 to 100.

The average length-diameter ratio of the shear thickening material satisfies the above range, and can improve the conductivity of ions and the effect of resisting external impact.

Optionally, the shear thickening material comprises a modified shear thickening material, the modification of the modified shear thickening material comprising an ion-conducting functional group;

the ion-conducting functional group is-SO ₃ Li、-SO ₃ At least one of Na.

Ion-conducting functional groups, meaning ion-conducting functional groups, e.g. lithium-containing sulfonic acid functional groups-SO ₃ Li。

In view of the fact that the shear thickening material is in the form of particles suspended in a solvent, which inhibit the transport of ions in an electrolyte, in order to increase the ion conductivity of the shear thickening material, the shear thickening material comprises a modified shear thickening material, the modification of which comprises ion-conducting functional groups, such that the modification of the ion-conducting functional groups renders the shear thickening material ion-conducting.

The surface of the shear thickening material is modified with the ion-conducting functional group, so that the transmission dynamics of lithium ions (for example, lithium batteries) in the electrolyte can be improved, the lithium ion transmission dynamics can be improved, the uniform deposition of lithium ions on the negative electrode is facilitated, and the problem of lithium dendrite growth can be solved.

Ion-conducting functional groups in the present applicationIncluding but not limited to-SO ₃ Li、-SO ₃ At least one of Na.

Optionally, the shear thickening material has a Dv50 range value of 50nm to 250nm.

Satisfying the above-described range for Dv50 of a shear thickening material may assist the shear thickening material in forming a shear thickening system in a solvent.

Optionally, the nano-oxide comprises a mesoporous nano-oxide;

and/or, the nano-organic polymer comprises a mesoporous organic polymer.

The pore diameter is between 2nm and 50nm and is called mesoporous. The mesoporous aperture is small, the specific surface area of the mesoporous nano oxide and/or the mesoporous nano organic polymer is large, and the mesoporous nano oxide and/or the mesoporous nano organic polymer is beneficial to modifying more materials and improving the ion transmission efficiency.

Optionally, the pore size range value of the nano-oxide and/or the nano-organic polymer is 2nm to 20nm;

and/or the nano oxide comprises at least one of silicon dioxide, zinc oxide, aluminum oxide, titanium dioxide, ferrous oxide and tin oxide;

And/or the nano organic polymer comprises at least one of nano polyvinyl chloride, nano polymethyl methacrylate, nano polystyrene and nano polyacrylamide.

The pore diameter of the nano oxide and/or the nano organic polymer meets the above range, so that the specific surface area of the nano oxide and/or the nano organic polymer can be increased, for example, the surface of the mesoporous oxide is subjected to sulfonation treatment, so that the surface of the mesoporous oxide is easier to be subjected to sulfonation treatment, more fold morphology is obtained, more electrolyte is captured, and the ion transmission is facilitated.

The nano-oxide in the present application includes, but is not limited to, at least one of silica, zinc oxide, aluminum oxide, titanium dioxide, ferrous oxide, and tin oxide. The nano organic polymer comprises at least one of nano polyvinyl chloride, nano polymethyl methacrylate, nano polystyrene and nano polyacrylamide.

It can be understood that the nano oxide, for example, the lone pair electron on the surface of the silicon dioxide is taken as an electron donor, the group is negatively charged, and can attract lithium ions of lithium salt (LiTFSi), after the silicon dioxide modifies the ion-conducting material, the transmission of the silicon dioxide in the electrolyte can be improved, further, the silicon dioxide adsorbs more lithium ions, the transmission of the lithium ions is further accelerated, and the battery dynamics is improved.

Optionally, the application also provides a preparation method of the electrolyte, which comprises the following steps:

preparing a shear thickening material having an average aspect ratio value in the range of 5 to 100, the shear thickening material comprising nano-oxides and/or nano-organic polymers;

sulfonating the shear thickening material to obtain a sulfonated shear thickening material;

mixing the sulfonated shear thickening material with lithium hydroxide solution and/or sodium hydroxide solution to obtain-SO ₃ Li and/or-SO ₃ Na-modified shear thickening material.

The application also provides an electrolyte comprising a solvent and an electrolyte as described;

alternatively, the electrolyte comprises a solvent and an electrolyte obtained by the method for preparing the electrolyte.

The electrolyte is dispersed in a solvent to form a shear thickening system, and the electrolyte is used in a battery, so that the performance of the battery against external impact can be improved.

Optionally, the mass of the shear thickening material is 20% to 50% by mass of the total mass of the electrolyte.

The mass of the shear thickening material in the above range may contribute to the formation of a shear thickening system.

The application also provides a solid electrolyte comprising an electrolyte as described.

It will be appreciated that the solid electrolyte is used in a battery, for example, in one embodiment, the positive electrode tab, the negative electrode tab, and the solid electrolyte are stacked in that order, placed in a battery case, and electrolyte is injected during assembly of the battery. The solid electrolyte can adsorb solvent and cation salt (such as lithium salt) to promote ion transmission, when the battery is impacted by the outside, the shear thickening material in the solid electrolyte and the solvent form a shear thickening system, the viscosity of the system is rapidly increased and is hard when the battery is impacted by the outside, so that the battery resists the impact of the outside, and the battery quickly returns to the initial state after the excitation is disappeared.

Optionally, the solid state electrolyte comprises a polymeric substrate and the shear thickening material disposed on the polymeric substrate.

The solid electrolyte comprises a polymeric substrate and a shear thickening material disposed on the polymeric substrate, it being understood that the solid electrolyte may be a membrane structure, i.e., the membrane structure of the solid electrolyte is formed from the polymeric substrate, with the shear thickening material being adsorbed on the polymeric substrate. The membrane layer structure formed by the polymer base material is a porous structure, can be soaked and absorbed in electrolyte, has good liquid-retaining capacity, has certain elasticity, and can buffer external force in the process of impacting the battery by external force.

Optionally, the polymer substrate comprises at least one of polyvinylidene fluoride polymer and polyethylene glycol polymer;

alternatively, the shear thickening material is modified with sulfonic acid groups;

and/or, the solid electrolyte contains electrolyte in the pore canal, and the electrolyte comprises solvent;

and/or the solid electrolyte has a thickness ranging from 50 μm to 300 μm;

and/or the solid state electrolyte has a porosity of 40% to 60%.

The polyvinylidene fluoride polymer comprises polyvinylidene fluoride homopolymer or copolymer of vinylidene fluoride and other fluorine-containing vinyl monomers.

The polyvinylidene fluoride polymer can be used as a binder and applied to a separator and/or a positive electrode sheet, and the polymer base material comprises the polyvinylidene fluoride polymer, so that the solid electrolyte has the binding property.

The polymer substrate includes, but is not limited to, at least one of polyvinylidene fluoride polymers, polyethylene glycol polymers. The polymeric substrate comprises a polyvinylidene fluoride polymer including, but not limited to, polyvinylidene fluoride-hexafluoropropylene copolymer.

The sulfonated shear thickening material has a radial structure of folds, can capture and retain a large amount of electrolyte, can improve the wettability of the solid electrolyte to the electrolyte, and can improve the liquid retention capacity of the solid electrolyte; further, consider CF in polyvinylidene fluoride based polymers _X The ionic dipole interaction between the group and the sulfo group of the nano oxide is in a honeycomb shape, so that the solid electrolyte has higher elasticity and good swelling property, is beneficial to adsorbing more electrolyte in a short time (namely, the adsorption rate of the solid electrolyte to the electrolyte is improved), and further improves the liquid absorption performance; it is understood that the imbibition rate directly affects the charge and discharge performance and cycle life of the battery, and that a faster imbibition rate can increase the charge rate and energy density of the battery while reducing voltage loss and heat dissipation of the battery during charge and discharge.

In one embodiment, the solid electrolyte is accommodated in the pore canal of the solid electrolyte, the electrolyte comprises a solvent, that is, the solid electrolyte can be soaked in the electrolyte to obtain the solid electrolyte adsorbed with the electrolyte, so that in one embodiment, the positive electrode sheet, the negative electrode sheet and the solid electrolyte are sequentially stacked in the process of assembling the battery and are placed in the battery shell. When the battery is impacted by the outside, the shear thickening material in the solid electrolyte and the solvent in the solid electrolyte form a shear thickening system, so that the capability of the battery for resisting the outside impact is improved.

The thickness of the solid electrolyte ranges from 50 mu m to 300 mu m, and the thickness of the solid electrolyte is set in the range, so that a proper amount of electrolyte can be contained, the ion transmission is improved, and meanwhile, the problem of electrolyte leakage caused by extrusion in the collision process of the battery is solved. It is understood that the impact resistance is strong as the thickness increases, but the transmission speed of lithium ions is affected as the thickness further increases, and for this reason, the thickness range of the solid electrolyte is considered to be 50 μm to 300 μm in combination.

The porosity of the solid electrolyte is 40% to 60%, and the liquid absorbing ability of the solid electrolyte can be improved.

Optionally, the application also provides a preparation method of the solid electrolyte, which comprises the following steps:

preparing a shear thickening material;

and dissolving the polymer in a solvent to obtain a first mixed solution, mixing and stirring the shear thickening material and the first mixed solution to obtain a second mixed solution, injecting the second mixed solution into a mold, and drying to obtain the solid electrolyte.

In preparing the solid electrolyte, the shear thickening material is prepared, and it is understood that the preparation of the shear thickening material may be directly prepared or may be a commercially available material.

In order to obtain the solid electrolyte, the polymer is dissolved in the solvent to obtain a first mixed solution, the shear thickening material and the first mixed solution are mixed and stirred to obtain a second mixed solution, the shear thickening material and the polymer are fully mixed, the second mixed solution is injected into a mould, and the solid electrolyte is obtained after drying.

The application also provides a battery comprising an electrolyte as described;

alternatively, the battery comprises an electrolyte as described;

alternatively, the battery comprises a solid electrolyte as described;

alternatively, the battery includes a solid electrolyte obtained by the method for producing a solid electrolyte as described;

optionally, the battery comprises a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte, wherein the positive electrode sheet and/or the separator comprises polyvinylidene fluoride polymer, and the electrolyte comprises the electrolyte.

Optionally, the positive electrode plate and the diaphragm are adjacently arranged, the surface of the positive electrode plate facing the diaphragm comprises polyvinylidene fluoride polymer, and the surface of the diaphragm facing the positive electrode plate comprises polyvinylidene fluoride polymer.

In one embodiment, a battery comprises a positive electrode sheet comprising a polyvinylidene fluoride polymer, a negative electrode sheet comprising a separator, and an electrolyte comprising an electrolyte as described; in this case, the electrolyte in the battery comprises a shear thickening material which can be adsorbed onto the polyvinylidene fluoride polymer to improve the ion transmission of the positive electrode plate, and further, the shear thickening material modified by sulfonic acid groups can be used with the polarity CF of the polyvinylidene fluoride polymer _X The groups are interacted to form a honeycomb shape, so that the liquid absorption performance of the positive pole piece is improved, and the ion transmission is improved.

In one embodiment, the battery comprises a positive electrode sheet, a negative electrode sheet, a separator comprising a polyvinylidene fluoride polymer, and an electrolyte comprising an electrolyte as described; in this case, the electrolyte in the cell comprises a shear thickening material that can adsorb to the polyvinylidene fluoride polymer to enhance ion transport of the separator, and further, the sulfonic acid group modified shear thickening material can be used in combination with the polar CF of the polyvinylidene fluoride polymer _X The groups are interacted to form a honeycomb shape, so that the liquid absorption performance of the diaphragm is improved, and the ion transmission is improved.

In one embodiment, the battery comprises a positive electrode plate, a negative electrode plate, a diaphragm and electrolyte, wherein the positive electrode plate and the diaphragm are adjacently arranged, the surface of the positive electrode plate facing the diaphragm comprises polyvinylidene fluoride polymer, the surface of the diaphragm facing the positive electrode plate comprises polyvinylidene fluoride polymer, and the electrolyte comprises the electrolyte. In this case, the electrolyte in the battery comprises a shear thickening material which can be adsorbed onto the polyvinylidene fluoride polymer, thereby not only improving the ion transmission between the positive electrode plate and the separator, but also the polarity CF of the polyvinylidene fluoride polymer can be obtained by modifying the shear thickening material with sulfonic acid groups _X The groups are interacted to form a honeycomb shape, so that the liquid absorption performance of the positive pole piece and the diaphragm is improved, and the ion transmission is improved; can alsoThe adhesive force between the diaphragm and the positive electrode plate is improved, specifically, the positive electrode plate and the diaphragm are adjacently arranged, the adjacent surfaces of the positive electrode plate and the diaphragm both comprise polyvinylidene fluoride polymers, the shear thickening material modified by sulfonic groups can interact with the polyvinylidene fluoride polymers on the adjacent surfaces, the adhesive property of the adjacent surfaces is improved, and the problem that gaps are generated between the positive electrode plate and the diaphragm is solved.

The application also provides an electric device, which comprises the battery.

The electrolyte of the application comprises a shear thickening material which is used in a battery solvent to form a shear thickening system which can passively respond to an external rapid stimulus, the viscosity of the system can be rapidly increased when the system encounters an external rapid impact, and the system becomes hard, thereby resisting the external impact and rapidly returning to an initial state after the stimulus is lost.

In addition, a shear thickening system is formed in a solvent by using a shear thickening material, and the shear thickening material forms an aggregate by using a shear thickening effect, so that the aggregate is mechanically hardened and can be blocked on the surface of the diaphragm, dendrites are prevented from puncturing the diaphragm, and the growth of dendrites is inhibited.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic illustration of an aspect ratio test;

fig. 2 is a schematic view of a battery cell according to an embodiment of the present application;

fig. 3 is an exploded view of a battery cell according to an embodiment of the present application shown in fig. 2;

fig. 4 is a schematic view of a battery module according to an embodiment of the present application;

fig. 5 is a schematic view of a battery pack according to an embodiment of the present application;

fig. 6 is an exploded view of the battery pack of the embodiment of the present application shown in fig. 5;

fig. 7 is a schematic view of an electric device in which a battery cell according to an embodiment of the present application is used as a power source.

Reference numerals illustrate:

the achievement of the objects, functional features and advantages of the present application will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The electrolyte and solid electrolyte of the present application, and the respective production methods, electrolytic solutions, batteries and devices thereof are specifically disclosed below, appropriately referring to the accompanying drawings. However, unnecessary detailed description may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of the actual same structure may be omitted. This is to avoid that the following description becomes unnecessarily lengthy, facilitating the understanding of those skilled in the art. Furthermore, the drawings and the following description are provided for a full understanding of the present application by those skilled in the art, and are not intended to limit the subject matter recited in the claims.

The "range" disclosed herein is defined in terms of lower and upper limits, with the given range being defined by the selection of a lower and an upper limit, the selected lower and upper limits defining the boundaries of the particular range. Ranges that are defined in this way can be inclusive or exclusive of the endpoints, and any combination can be made, i.e., any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are also contemplated. Furthermore, if the minimum range values 1 and 2 are listed, and if the maximum range values 3,4 and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise indicated, the numerical range "a-b" represents a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed throughout, and "0-5" is simply a shorthand representation of a combination of these values. When a certain parameter is expressed as an integer of 2 or more, it is disclosed that the parameter is, for example, an integer of 2, 3,4, 5, 6, 7, 8, 9, 10, 11, 12 or the like.

All embodiments of the application and alternative embodiments may be combined with each other to form new solutions, unless otherwise specified.

All technical features and optional technical features of the application may be combined with each other to form new technical solutions, unless specified otherwise.

All the steps of the present application may be performed sequentially or randomly, preferably sequentially, unless otherwise specified. For example, the method comprises steps (a) and (b), meaning that the method may comprise steps (a) and (b) performed sequentially, or may comprise steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), may include steps (a), (c) and (b), may include steps (c), (a) and (b), and the like.

In order to solve the technical problems, the application provides an electrolyte, which aims to improve the external impact resistance of a battery.

The electrolyte comprises a shear thickening material having an average aspect ratio value in the range of 5 to 100.

In one embodiment, the average aspect ratio value of the shear thickening material is in the range of 5 to 100, the shear thickening material comprising nano-oxides and/or nano-organic polymers.

Aspect ratio, the ratio of longest diameter R1 passing through the interior of the particle to longest diameter R2 perpendicular thereto; using particle image workstation testing (e.g., VISION 210-D particle image workstation), the apparatus uses the principle of imaging, as shown in fig. 1, it is possible to find R1 and R2 in the particle projection plane and obtain the ratio thereof, where R1 is the longest diameter passing through the interior of the particle, R2 is the longest diameter perpendicular to R1, and for convenience of understanding, for example, when the morphology of the particle is a cylinder, the height of the cylinder is 20nm, the bottom diameter of the cylinder is 5nm, the longest diameter R1 inside the cylinder is the value of the height, and the longest diameter R2 perpendicular to the height is the value of the bottom diameter.

It is understood that the average aspect ratio is the average of the aspect ratios of all shear thickening materials.

The values 5 to 100 described above include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, point values in the embodiments and values of 5, 8, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, etc., and range values between any two of the above-described point values.

For example, in one embodiment, the shear thickening material is dispersed in an electrolyte to form a shear thickening fluid, which is a non-newtonian fluid, such that an electrolyte is obtained that is capable of achieving a liquid-solid-liquid transition, which combines the high safety of a solid electrolyte with the excellent electrochemical properties of a liquid electrolyte. In a steady state, the shear thickening electrolyte is in a liquid state; under the action of external shearing force, the shear thickening material forms an aggregate, the viscosity of the system is increased sharply, the mechanical strength is improved, and the energy dissipation effect can be achieved; when the shear force is removed, it returns to steady state again.

In one embodiment, the average aspect ratio of the shear thickening material ranges from 20 to 100.

The values 20 to 100 include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, point values in the embodiments and values of 20, 30, 40, 50, 60, 70, 80, 90, 100, etc., and range values between any two of the above-mentioned point values.

In one embodiment, the shear thickening material comprises a modified shear thickening material, and the modification of the modified shear thickening material comprises an ion-conducting functional group.

Ion-conducting functional groups, meaning ion-conducting materials, e.g. lithium-ion-containing sulfonic acid functional groups-SO ₃ Li。

In one embodiment, the ion-conducting functional group comprises-SO ₃ Li、-SO ₃ At least one of Na.

The ion-conducting functional groups in the present application are not limited to-SO ₃ Li、-SO ₃ At least one of the Na, for example, when applied to a lithium battery, the ion-conducting functional group may include-SO ₃ Li, i.e. shear thickening material is modified with-SO ₃ Li, to enhance the transport of lithium ions. When applied to sodium cells, the ion-conducting functional groups may include-SO ₃ Na, i.e. shear thickening material is modified with-SO ₃ Na, which is used to enhance the transport of sodium ions.

It will be appreciated that the surface modification of the shear thickening material leads to the ionic functionality-SO ₃ Li, i.e. the reaction of incorporating lithium on the surface of a shear thickening material, is called para-shearLithiation of thickening materials, e.g., in one embodiment, siO ₂ The nano particles are in excess of H ₂ SO ₄ Soaking in water for 24 hr, centrifuging, washing with deionized water for three times, and vacuum drying at 70deg.C to obtain sulfated silica nanoparticle (SiO) ₂ -SO ₃ H) Mixing sulfated silica nanoparticles with lithium hydroxide solution to obtain-SO ₃ Li modified nano-oxides.

In one embodiment, the morphology of the shear thickening material comprises at least one of a rod or a plate.

The morphology of the shear thickening material in the present application comprises at least one of a rod or a plate. It will be appreciated that the rod-like shape includes a columnar structure, which may be, for example, cylindrical, prismatic, etc., but may also be, of course, irregular, cylindrical, prismatic, etc.

In one embodiment, the shear thickening material has a Dv50 value in the range of 50nm to 250nm; alternatively, the modified shear thickening material has a Dv50 value in the range of 80nm to 300nm.

Dv50, the particle size corresponding to a cumulative particle size distribution percentage of one sample reaching 50%. Its physical meaning is that the particle size is greater than 50% of its particle size, and less than 50% of its particle size, also known as median or median particle size, dv 50. Dv50 is often used to represent the average particle size of the powder.

Dv50 may be tested using methods well known in the art. By way of example, reference may be made to GB/T19077-2016 for characterization tests using a Markov laser particle sizer, such as a Malvern Mastersizer-3000 or the like.

A Dv50 of the modified shear-thickening material meeting the above ranges may contribute to the formation of a shear-thickening system of the modified shear-thickening material in a solvent.

The above 50nm to 250nm values include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, the dot values in the embodiments and the range values between 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, 150nm, 180nm, 200nm, 220nm, 240nm, 250nm, and the like.

The values of 80nm to 300nm described above include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, point values in the embodiments and values of 80nm, 90nm, 100nm, 120nm, 150nm, 180nm, 200nm, 220nm, 240nm, 250nm, 280nm, 300nm, and the like, and ranges between any two of the above-described point values.

In one embodiment, the shear thickening material has a Dv50 value in the range of 100nm to 200nm; alternatively, the modified shear thickening material has a Dv50 value in the range of 120nm to 240nm.

The values of 100nm to 200nm described above include the minimum and maximum values of the range, and each value between such minimum and maximum values, and specific examples include, but are not limited to, point values in the examples and values of 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, etc., and ranges between any two of the above-described point values.

The values of 120nm to 240nm mentioned above include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, point values in the embodiments and values of 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, 220nm, 240nm, etc., and range values between any two of the above-mentioned point values.

In one embodiment, the nano-oxide comprises a mesoporous nano-oxide; and/or, the nano-organic polymer comprises a mesoporous organic polymer.

In one embodiment, the nano-oxide and/or nano-organic polymer has a pore size ranging from 2nm to 20nm.

It will be appreciated that the reaction of introducing sulfonic acid groups on the surface of the material is known as sulfonation, e.g., in one embodiment, siO ₂ The nano particles are in excess of H ₂ SO ₄ Soaking in water for 24 hr, centrifuging, washing with deionized water for three times, and vacuum drying at 70deg.C to obtain sulfated silica nanoparticle (SiO) ₂ -SO ₃ H)。

The above-mentioned 2nm to 20nm values include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, point values in the embodiments and values of 2nm, 4nm, 5nm, 7nm, 9nm, 10nm, 12nm, 14nm, 15nm, 18nm, 20nm, etc., and range values between any two of the above-mentioned point values.

In one embodiment, the nano-oxide comprises at least one of silicon dioxide, zinc oxide, aluminum oxide, titanium dioxide, ferrous oxide, and tin oxide; and/or the nano organic polymer comprises at least one of nano polyvinyl chloride, nano polymethyl methacrylate, nano polystyrene and nano polyacrylamide.

In an embodiment, the present application also provides a method for preparing an electrolyte, including: preparing a shear thickening material having an average aspect ratio in the range of 5 to 100; sulfonating the shear thickening material to obtain a sulfonated shear thickening material; mixing the sulfonated shear thickening material with lithium hydroxide solution and/or sodium hydroxide solution to obtain-SO ₃ Li and/or-SO ₃ Na-modified shear thickening material.

In one embodiment, the present application also provides an electrolyte comprising a solvent and an electrolyte as described above; alternatively, the electrolyte may comprise a solvent and an electrolyte obtained by the method for producing an electrolyte as described above.

In one embodiment, the mass of the shear thickening material is 20% to 50% by mass of the total mass of the electrolyte.

The values of 20% to 50% above include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, the dot values in the embodiments and 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc., and the range values between any two of the dot values above.

In one embodiment, the mass of the shear thickening material is 25% to 45% by mass of the total mass of the electrolyte.

The values of 25% to 45% above include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, the point values in the embodiments and 25%, 27%, 29%, 30%, 32%, 35%, 37%, 38%, 40%, 42%, 43%, 45%, etc., and the range values between any two of the above-mentioned point values.

In one embodiment, the mass of the modified shear thickening material is 12% to 55% by mass of the total mass of the electrolyte.

The mass percentage of the modified shear thickening material in the above range can contribute to the formation of a shear thickening system. The modifications of the modified shear thickening material include ion-conducting functional groups, and the modified shear thickening material may also improve ion transport.

The values of 12% to 55% above include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, point values in the embodiments and 12%, 13%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 53%, 55%, etc., and range values between any two of the above-mentioned point values.

In one embodiment, the mass of the modified shear thickening material is 25% to 45% by mass of the total mass of the electrolyte.

In one embodiment, the solvent comprises at least two of ethylene carbonate, diethyl carbonate, propylene carbonate, dimethyl carbonate, ethylmethyl carbonate, fluoroethylene carbonate, and fluorodiethyl carbonate; and/or the mass of the solvent accounts for 30 to 80 percent of the total mass of the electrolyte; and/or the electrolyte further comprises a cationic salt, wherein the cationic salt comprises a lithium salt, and the lithium salt comprises at least one of lithium hexafluorophosphate, lithium difluorophosphate, lithium perchlorate, lithium bis (trifluoromethanesulfonyl) imide, lithium bis (oxalato) borate, lithium difluoro (oxalato) borate, lithium bis (fluorosulfonyl) imide and lithium 4, 5-dicyano-2-trifluoromethylimidazole; and/or the electrolyte further comprises a cationic salt, wherein the concentration of the cationic salt in the electrolyte is 0.8mol/L to 1.3mol/L; and/or the electrolyte further comprises a film forming additive, wherein the film forming additive comprises at least one of vinylene carbonate, fluoroethylene carbonate, ethylene carbonate and 1, 3-propane sultone; and/or the electrolyte further comprises a film forming additive, wherein the mass of the film forming additive accounts for 0.1-2% of the total mass of the electrolyte.

Solvents in the present application include, but are not limited to, at least two of ethylene carbonate, diethyl carbonate, propylene carbonate, dimethyl carbonate, methylethyl carbonate, fluoroethylene carbonate, and fluorodiethyl carbonate.

The mass of the solvent in the application accounts for 30-80% of the total mass of the electrolyte.

The electrolyte in the present application further comprises a cationic salt including a lithium salt including, but not limited to, at least one of lithium hexafluorophosphate, lithium difluorophosphate, lithium perchlorate, lithium bis (trifluoromethanesulfonyl) imide, lithium bis (oxalato) borate, lithium difluoro (oxalato) borate, lithium bis (fluorosulfonyl) imide, and lithium 4, 5-dicyano-2-trifluoromethylimidazole.

The electrolyte further comprises a cationic salt, and the concentration of the cationic salt in the electrolyte is 0.8mol/L to 1.3mol/L.

The electrolyte further includes a film forming additive including, but not limited to, at least one of vinylene carbonate, fluoroethylene carbonate, ethylene carbonate, 1, 3-propane sultone.

The electrolyte also comprises a film forming additive, wherein the mass of the film forming additive accounts for 0.1 to 2 percent of the total mass of the electrolyte.

The values of 30% to 80% above include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, point values in the embodiments and values of 30%, 32%, 35%, 37%, 38%, 40%, 42%, 43%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, etc., and range values between any two of the above-mentioned point values.

Among the above 0.8mol/L to 1.3mol/L, values include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, the dot values in the examples and the range values between any two of the dot values described above, 0.8mol/L, 0.9mol/L, 1.0mol/L, 1.1mol/L, 1.2mol/L, 1.3mol/L, and the like.

The values of 0.1% to 2% above include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, point values in the embodiments and range values between 0.1%, 0.2%, 0.5%, 0.6%, 0.8%, 1%, 1.1%, 1.2%, 1.5%, 1.6%, 1.8%, 2%, and the like, and any two point values above.

In one embodiment, the present application also provides a solid electrolyte, including, for example, an electrolyte.

Solid electrolyte, which is a solid ion conductor electrolyte.

It will be appreciated that the solid electrolyte is used in a battery, for example, in one embodiment, the positive electrode tab, the negative electrode tab, and the solid electrolyte are stacked in that order, placed in a battery case, and electrolyte is injected during assembly of the battery. The solid electrolyte can adsorb solvent and cation salt to promote ion transmission, and when the battery is impacted by outside, the shear thickening material in the solid electrolyte and the solvent form a shear thickening system, the viscosity of the system is rapidly increased and becomes hard when the rapid external impact is met, so that the solid electrolyte resists the external impact and returns to the initial state rapidly after the excitation is lost.

In one embodiment, a solid state electrolyte includes a polymer substrate and a shear thickening material disposed on the polymer substrate.

In one embodiment, the polymer substrate comprises at least one of polyvinylidene fluoride polymer and polyethylene glycol polymer; alternatively, the polymeric substrate comprises a polyvinylidene fluoride-based polymer comprising a polyvinylidene fluoride-hexafluoropropylene copolymer.

The polyvinylidene fluoride polymer can be used as a binder and applied to a diaphragm and/or a positive electrode plate, and the polymer base material comprises the polyvinylidene fluoride polymer, so that the solid electrolyte has binding performance, and the solid electrolyte can be applied to a battery, so that the binding property of the solid electrolyte and the positive electrode plate can be improved, the contact between the solid electrolyte and the positive electrode plate is tighter, and the ion transmission is facilitated.

In one embodiment, the shear thickening material is modified with sulfonic acid groups; and/or, the solid electrolyte is contained in the pore canal, and the electrolyte comprises a solvent; and/or the solid electrolyte has a thickness in the range of 50 μm to 300 μm; and/or the solid state electrolyte has a porosity of 40% to 60%.

The shear thickening material is modified with sulfonic acid groups and sulfonatedThe shear thickening material has a radial structure of folds, can capture and retain a large amount of electrolyte, can improve the wettability of the solid electrolyte to the electrolyte, and can improve the liquid retention capacity of the solid electrolyte; further, consider CF in polyvinylidene fluoride based polymers _X The ionic dipole interaction between the group and the sulfo group of the nano oxide is in a honeycomb shape, so that the solid electrolyte has higher elasticity and good swelling property, is favorable for adsorbing more electrolyte in a short time (namely, the adsorption rate of the solid electrolyte to the electrolyte is improved), and further improves the imbibition performance.

The thickness of the solid electrolyte ranges from 50 mu m to 300 mu m, and the thickness of the solid electrolyte is set in the range, so that a proper amount of electrolyte can be contained, the ion transmission is improved, and meanwhile, the problem of electrolyte leakage caused by extrusion in the collision process of the battery is solved.

The porosity of the solid electrolyte is 40% to 60%, and the liquid absorption capacity and porosity of the solid electrolyte can be improved.

The calculation formula is p= [ V/V0 ]. Times.100%. V0 is the volume of the material in its natural state and V is the volume of all voids in the material.

The above 50 μm to 300 μm, the values include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, dot values in the examples and range values between any two of the above 50 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm, 220 μm, 240 μm, 260 μm, 280 μm, 300 μm, and the like.

Among the above 40% to 60%, values include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, point values in the embodiments and values of 40%, 42%, 44%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, etc., and range values between any two of the above-mentioned point values.

In an embodiment, the present application further provides a method for preparing a solid electrolyte, including: preparing a shear thickening material; and dissolving the polymer in a solvent to obtain a first mixed solution, mixing and stirring the shear thickening material and the first mixed solution to obtain a second mixed solution, injecting the second mixed solution into a mold, and drying to obtain the solid electrolyte.

In one embodiment, in the step of preparing the shear thickening material, comprising: soaking the nano oxide in sulfuric acid to obtain sulfonated nano oxide.

That is, the sulfonic acid group can be modified on the surface of the nano oxide by the method. For example, in one embodiment, siO ₂ The nano particles are in excess of H ₂ SO ₄ Soaking in water for 24 hr, centrifuging, washing with deionized water for three times, and vacuum drying at 70deg.C to obtain sulfated silica nanoparticle (SiO) ₂ -SO ₃ H) A. The invention relates to a method for producing a fibre-reinforced plastic composite It will be appreciated that, for effective sulphonation,the sulfuric acid may be concentrated sulfuric acid, for example, the sulfuric acid concentration is 98% or more.

In one embodiment, after the step of immersing the nano-oxide in sulfuric acid to obtain the sulfonated nano-oxide, the method further comprises: mixing the sulfonated nano oxide with lithium hydroxide solution to obtain-SO ₃ Li modified nano-oxides.

To modify the ion-conducting functional groups on the nano-oxide, the sulfonated nano-oxide is further mixed with a lithium hydroxide solution to obtain-SO ₃ Li modified nano-oxides. It can be understood that in order to effectively modify lithium, lithium hydroxide needs to be excessive, so that the pre-lithium is ensured to be sufficient; for example, at least 0.35g of lithium hydroxide is used for 1g of sulfonated nano oxide, i.e., the ratio of the mass of the sulfonated nano oxide to the mass of the lithium hydroxide is 2.86 or more.

In one embodiment, the ratio of the mass of polymer to the mass of shear thickening material is 80 to 120; and/or the polymer comprises a polyvinylidene fluoride polymer; and/or the solvent comprises at least one of acetone, cyclohexanone and methyl isobutyl ketone.

In the process of preparing the solid electrolyte, the ratio of the mass of the polymer to the mass of the shear thickening material is 80 to 120; polymers include, but are not limited to, polyvinylidene fluoride based polymers; the solvent includes, but is not limited to, at least one of acetone, cyclohexanone, methyl isobutyl ketone.

The values 80 to 120 include the minimum value and the maximum value of the range, and each value between such minimum value and maximum value, and specific examples include, but are not limited to, point values in the embodiment and values of 80, 85, 90, 95, 100, 110, 115, 120, etc., and range values between any two of the above-mentioned point values.

In one embodiment, after the step of dissolving the polymer in the solvent to obtain a first mixed solution, mixing and stirring the shear thickening material with the first mixed solution to obtain a second mixed solution, injecting the second mixed solution into a mold, and drying to obtain the solid electrolyte, the method further comprises: and immersing the solid electrolyte in the electrolyte, and taking out the solid electrolyte after the electrolyte is contained in the pore canal of the solid electrolyte.

In order to obtain the solid electrolyte having the electrolyte adsorbed therein, the obtained solid electrolyte may be immersed in the electrolyte, and the solid electrolyte may be taken out after the electrolyte is contained in the cells of the solid electrolyte.

In one embodiment, the application also provides a battery comprising an electrolyte as described above; alternatively, the battery includes an electrolyte as described above; alternatively, the battery includes a solid electrolyte as described above; alternatively, the battery includes a solid electrolyte obtained by the above-described method for producing a solid electrolyte.

In one embodiment, the battery comprises a positive electrode sheet, a negative electrode sheet, a separator, and an electrolyte, the positive electrode sheet and/or the separator comprising polyvinylidene fluoride based polymer, the electrolyte comprising an electrolyte as described above.

In an embodiment, the positive electrode sheet is disposed adjacent to the separator, the surface of the positive electrode sheet facing the separator comprises polyvinylidene fluoride polymer, and the surface of the separator facing the positive electrode sheet comprises polyvinylidene fluoride polymer.

In one embodiment, the battery comprises a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte, wherein the positive electrode sheet comprises polyvinylidene fluoride polymer, and the electrolyte comprises electrolyte; in this case, the electrolyte in the battery comprises a shear thickening material which can be adsorbed onto the polyvinylidene fluoride polymer to improve the ion transmission of the positive electrode plate, and further, the shear thickening material modified by sulfonic acid groups can be used with the polarity CF of the polyvinylidene fluoride polymer _X The groups are interacted to form a honeycomb shape, so that the liquid absorption performance of the positive pole piece is improved, and the ion transmission is improved.

In one embodiment, the battery comprises a positive electrode sheet, a negative electrode sheet, a separator comprising a polyvinylidene fluoride polymer, and an electrolyte comprising an electrolyte; in this case, the electrolyte in the cell comprises a shear thickening material which can be adsorbed onto the polyvinylidene fluoride polymer to improve ion transport of the separator, and further, the shear thickening material modified with sulfonic acid groups can be used in combination with polyvinylidene fluoridePolarity CF of vinyl polymer _X The groups are interacted to form a honeycomb shape, so that the liquid absorption performance of the diaphragm is improved, and the ion transmission is improved.

In one embodiment, the battery comprises a positive electrode plate, a negative electrode plate, a diaphragm and electrolyte, wherein the positive electrode plate and the diaphragm are adjacently arranged, the surface of the positive electrode plate facing the diaphragm comprises polyvinylidene fluoride polymer, the surface of the diaphragm facing the positive electrode plate comprises polyvinylidene fluoride polymer, and the electrolyte comprises the electrolyte. In this case, the electrolyte in the battery comprises a shear thickening material which can be adsorbed onto the polyvinylidene fluoride polymer, thereby not only improving the ion transmission between the positive electrode plate and the separator, but also the polarity CF of the polyvinylidene fluoride polymer can be obtained by modifying the shear thickening material with sulfonic acid groups _X The groups are interacted to form a honeycomb shape, so that the liquid absorption performance of the positive pole piece and the diaphragm is improved, and the ion transmission is improved; the adhesive force between the diaphragm and the positive electrode plate can be improved, in particular, the positive electrode plate and the diaphragm are adjacently arranged, the adjacent surfaces of the positive electrode plate and the diaphragm both comprise polyvinylidene fluoride polymers, the shear thickening material modified by the sulfonic group can interact with the polyvinylidene fluoride polymers on the adjacent surfaces, the adhesive property of the adjacent surfaces is improved, and the problem that gaps are generated between the positive electrode plate and the diaphragm is solved.

In an embodiment, the application further provides an electric device, which comprises the battery.

The battery adopts all the technical schemes of all the embodiments, so that the battery has at least all the beneficial effects brought by the technical schemes of the embodiments, and the description is omitted herein.

In one embodiment, a lithium ion battery comprises a positive electrode, a negative electrode, a diaphragm and an electrolyte, wherein the positive electrode sheet, the diaphragm and the negative electrode sheet are sequentially stacked or wound into a winding core, the winding core is packaged, and then the electrolyte (a shear thickening material is added in the electrolyte) is injected, and then the winding core is sealed. It is understood that the shape of the lithium ion battery is prismatic, soft pack or cylindrical. The positive electrode material of the lithium ion battery is a ternary material or a lithium iron phosphate material. The lithium ion battery cathode material is one or more of graphite, silicon carbon and silicon oxygen.

In one embodiment, a battery pack comprises an electrolyte added with a shear thickening material, wherein the battery pack comprises an upper box body, a lower box body, a heat insulation plate, a water cooling plate and a lithium ion battery; an insulation board is arranged in the battery pack, the battery pack comprises a bottom water cooling board for heat management of the battery pack, and the water cooling board is fixed at the bottom of the lithium ion battery. The bottom of the lithium ion battery is bonded and fixed with the water cooling plate through the heat conduction structural adhesive, and the top of the lithium ion battery is bonded and fixed with the chassis floor through the heat conduction structural adhesive.

In one embodiment, a vehicle includes a chassis, a lithium ion battery (including an electrolyte with a shear thickening material added) that does not carry a battery pack, the lithium ion battery being directly disposed in the chassis.

The battery secondary battery, the battery module, the battery pack, and the electric device according to the present application will be described below with reference to the drawings.

In one embodiment of the present application, a secondary battery is provided.

In general, a secondary battery includes a positive electrode tab, a negative electrode tab, an electrolyte, and a separator. During the charge and discharge of the battery, active ions are inserted and extracted back and forth between the positive electrode plate and the negative electrode plate. The electrolyte plays a role in ion conduction between the positive electrode plate and the negative electrode plate. The diaphragm is arranged between the positive pole piece and the negative pole piece, mainly plays a role in preventing the positive pole piece and the negative pole piece from being short-circuited, and can enable ions to pass through. The separator is the improved separator of the present application described above.

The positive pole piece comprises a positive current collector and a positive film layer arranged on at least one surface of the positive current collector.

As an example, the positive electrode current collector has two surfaces opposing in its own thickness direction, and the positive electrode film layer is provided on either one or both of the two surfaces opposing the positive electrode current collector.

In some embodiments, the positive current collector may employ a metal foil or a composite current collector. For example, as the metal foil, aluminum foil may be used. The composite current collector may include a polymeric material base layer and a metal layer formed on at least one surface of the polymeric material base layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

In some embodiments, when the secondary battery is a lithium ion battery, the positive electrode active material may be a positive electrode active material for a lithium ion battery, which is well known in the art. As an example, the positive electrode active material may include at least one of the following materials: olivine structured lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material may be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (e.g., liCoO) ₂ ) Lithium nickel oxide (e.g. LiNiO) ₂ ) Lithium manganese oxide (e.g. LiMnO ₂ 、LiMn ₂ O ₄ ) Lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., liNi) _1/3 Co _1/ ₃ Mn _1/3 O ₂ (also referred to as NCM) ₃₃₃ ）、LiNi _0.5 Co _0.2 Mn _0.3 O ₂ (also referred to as NCM) ₅₂₃ ）、LiNi _0.5 Co _0.25 Mn _0.25 O ₂ (also referred to as NCM) ₂₁₁ ）、LiNi _0.6 Co _0.2 Mn _0.2 O ₂ (also referred to as NCM) ₆₂₂ ）、LiNi _0.8 Co _0.1 Mn _0.1 O ₂ (also referred to as NCM) ₈₁₁ ) Lithium nickel cobalt aluminum oxide (e.g. LiNi _0.85 Co _0.15 Al _0.05 O ₂ ) And at least one of its modified compounds and the like. Examples of olivine structured lithium-containing phosphates may include, but are not limited to, lithium iron phosphate (e.g., liFePO ₄ (also abbreviated as LFP)), composite material of lithium iron phosphate and carbon, and manganese lithium phosphate (such as LiMnPO) ₄ ) At least one of a composite material of lithium manganese phosphate and carbon, and a composite material of lithium manganese phosphate and carbon.

The battery is charged and discharged with the release and consumption of Li, and the molar contents of Li are different when the battery is discharged to different states. In the application, the molar content of Li is the initial state of the material, namely the state before charging, and the molar content of Li can be changed after charge and discharge cycles when the positive electrode material is applied to a battery system.

In the application, in the list of the positive electrode materials, the molar content of O is only a theoretical state value, the molar content of oxygen can be changed due to the oxygen release of the crystal lattice, and the actual molar content of O can be floated.

In some embodiments, the positive electrode film layer further optionally includes a binder. As an example, the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a fluoroacrylate resin.

In some embodiments, the positive electrode film layer further optionally includes a conductive agent. As an example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

In some embodiments, the positive electrode sheet may be prepared by: dispersing the above components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and any other components, in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry; and (3) coating the positive electrode slurry on a positive electrode current collector, and obtaining a positive electrode plate after the procedures of drying, cold pressing and the like.

The negative electrode plate comprises a negative electrode current collector and a negative electrode film layer arranged on at least one surface of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material.

As an example, the anode current collector has two surfaces opposing in its own thickness direction, and the anode film layer is provided on either one or both of the two surfaces opposing the anode current collector.

In some embodiments, the negative electrode current collector may employ a metal foil or a composite current collector. For example, as the metal foil, copper foil may be used. The composite current collector may include a polymeric material base layer and a metal layer formed on at least one surface of the polymeric material base material. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

In some embodiments, the anode active material may employ an anode active material for a battery, which is well known in the art. As an example, the anode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, and the like. The silicon-based material may be at least one selected from elemental silicon, silicon oxygen compounds, silicon carbon composites, silicon nitrogen composites, and silicon alloys. The tin-based material may be at least one selected from elemental tin, tin oxide, and tin alloys. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery anode active material may be used. These negative electrode active materials may be used alone or in combination of two or more.

In some embodiments, the negative electrode film layer further optionally includes a binder. The binder may be at least one selected from Styrene Butadiene Rubber (SBR), polyacrylic acid (PAA), sodium Polyacrylate (PAAs), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium Alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).

In some embodiments, the negative electrode film layer further optionally includes a conductive agent. The conductive agent is at least one selected from superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.

In some embodiments, the negative electrode film layer may optionally further include other adjuvants, such as thickening agents (e.g., sodium carboxymethyl cellulose (CMC-Na)), and the like.

In some embodiments, the negative electrode sheet may be prepared by: dispersing the above components for preparing the negative electrode sheet, such as a negative electrode active material, a conductive agent, a binder and any other components, in a solvent (e.g., deionized water) to form a negative electrode slurry; and coating the negative electrode slurry on a negative electrode current collector, and obtaining a negative electrode plate after the procedures of drying, cold pressing and the like.

The electrolyte plays a role in ion conduction between the positive electrode plate and the negative electrode plate. The application is not particularly limited in the kind of electrolyte, and may be selected according to the need.

In some embodiments, the electrolyte is an electrolyte. The electrolyte includes an electrolyte salt and a solvent.

In some embodiments, the electrolyte further optionally includes an additive. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives capable of improving certain properties of the battery, such as additives that improve the overcharge performance of the battery, additives that improve the high or low temperature performance of the battery, and the like.

In some embodiments, the positive electrode tab, the negative electrode tab, and the separator may be manufactured into an electrode assembly through a winding process or a lamination process.

In some embodiments, the battery cell may include an outer package. The outer package may be used to encapsulate the electrode assembly and electrolyte described above.

In some embodiments, the exterior packaging of the battery cell may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, or the like. The outer package of the battery cell may also be a pouch, such as a pouch-type pouch. The material of the flexible bag may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.

The shape of the battery cell is not particularly limited in the present application, and may be cylindrical, square or any other shape. For example, fig. 2 is a square-structured battery cell 5 as one example.

In some embodiments, referring to fig. 3, the outer package may include a housing 51 and a cover 53. The housing 51 may include a bottom plate and a side plate connected to the bottom plate, where the bottom plate and the side plate enclose a receiving chamber. The housing 51 has an opening communicating with the accommodation chamber, and the cover plate 53 can be provided to cover the opening to close the accommodation chamber. The positive electrode sheet, the negative electrode sheet, and the separator may be formed into the electrode assembly 52 through a winding process or a lamination process. The electrode assembly 52 is packaged in the receiving chamber. The electrolyte is impregnated in the electrode assembly 52. The number of the electrode assemblies 52 included in the battery cell 5 may be one or more, and those skilled in the art may select the number according to specific practical requirements.

In some embodiments, the battery cells may be assembled into a battery module, and the number of battery cells included in the battery module may be one or more, and the specific number may be selected by one skilled in the art according to the application and capacity of the battery module.

Fig. 4 is a battery module 4 as an example. Referring to fig. 4, in the battery module 4, a plurality of battery cells 5 may be sequentially arranged in the longitudinal direction of the battery module 4. Of course, the arrangement may be performed in any other way. The plurality of battery cells 5 may be further fixed by fasteners.

Alternatively, the battery module 4 may further include a housing having an accommodating space in which the plurality of battery cells 5 are accommodated.

In some embodiments, the above battery modules may be further assembled into a battery pack, and the number of battery modules included in the battery pack may be one or more, and a specific number may be selected by those skilled in the art according to the application and capacity of the battery pack.

Fig. 5 and 6 are battery packs 1 as an example. Referring to fig. 5 and 6, a battery case and a plurality of battery modules 4 disposed in the battery case may be included in the battery pack 1. The battery box includes an upper box body 2 and a lower box body 3, and the upper box body 2 can be covered on the lower box body 3 and forms a closed space for accommodating the battery module 4. The plurality of battery modules 4 may be arranged in the battery box in any manner.

In addition, the application also provides an electric device which comprises at least one of the secondary battery, the battery module or the battery pack. The secondary battery, the battery module, or the battery pack may be used as a power source of the electric device, and may also be used as an energy storage unit of the electric device. The power utilization device may include, but is not limited to, mobile devices (e.g., cell phones, notebook computers, etc.), electric vehicles (e.g., electric only vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, and the like.

As the power consumption device, a battery cell, a battery module, or a battery pack may be selected according to the use requirements thereof.

Fig. 7 is an electrical device as an example. The electric device is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle or the like. To meet the high power and high energy density requirements of the power device for the battery cells, a battery pack or battery module may be employed.

As another example, the device may be a cell phone, tablet computer, notebook computer, or the like. The device is generally required to be light and thin, and a battery cell can be used as a power supply.

Examples

Example 1

Shear thickening material: siO (SiO) ₂ The nanometer particle (rod-shaped) has Dv50 of 100nm, mesoporous aperture of 10nm, average length-diameter ratio of 100:1, and the mass of the shear thickening material accounts for 20% of the total mass of the electrolyte.

Preparation of negative pole piece

Active substances of graphite, silicon, a conductive agent of acetylene black, a high molecular polymer (polyimide) and a thickener of sodium carboxymethyl cellulose (CMC-Na) are dissolved in solvent deionized water according to the weight ratio of 90:5:2:2:1, and are uniformly mixed with the solvent deionized water to prepare negative electrode slurry, the slurry is coated on copper foil, and the negative electrode slurry is dried and then subjected to cold pressing slitting to obtain the anode electrode plate.

Preparation of positive electrode plate

Dissolving an anode active material NCM, a conductive agent acetylene black and a binder polyvinylidene fluoride (PVDF) in a weight ratio of 96.5:1.5:2 into a solvent N-methylpyrrolidone (NMP), and fully stirring and uniformly mixing to obtain anode slurry; and uniformly coating the anode slurry on an anode current collector with a bottom coating, and drying, cold pressing and cutting to obtain an anode plate.

Diaphragm

The diaphragm is a PE diaphragm, and PVDF and an alumina coating are coated on the surface of the diaphragm, so that the adhesion and the heat resistance are improved.

Electrolyte solution

Mixing Ethylene Carbonate (EC), ethylmethyl carbonate (EMC) and diethyl carbonate (DEC) according to a volume ratio of 1:1:1, and then mixing LiPF ₆ : liFSI (2:8) is uniformly dissolved in the solution to obtain an electrolyte. In the electrolyte, the concentration of lithium salt was 1mol/L.

Battery preparation

Sequentially stacking the positive electrode plate, the isolating film and the negative electrode plate, enabling the isolating film to be positioned between the positive electrode plate and the negative electrode plate to play a role of isolation, then winding to obtain a bare cell, welding electrode lugs on the bare cell, respectively adhering buffer pads on two sides of the JR to the position of a legend, loading the bare cell into an aluminum shell, baking at 80 ℃ for removing water, injecting electrolyte, and sealing to obtain the uncharged battery. And the uncharged battery is subjected to the procedures of standing, hot and cold pressing, formation, shaping, capacity testing and the like in sequence, so that a lithium ion battery product is obtained.

Example 2, example 3, example 5, example 6

Based on example 1, the mass percentage of the shear thickening material to the total mass of the electrolyte was adjusted, and the average aspect ratio of the shear thickening material was adjusted.

Example 4

On the basis of example 2, the shear-thickening material was adjusted.

Example 7

On the basis of example 2, the shear thickening material was sulphonated.

Preparation of a shear thickening material:

SiO ₂ sulfonation: siO is made of ₂ Nanoparticles (Dv 50 of 150 nm) at H ₂ SO ₄ (concentration 99%, siO) ₂ Soaking in 5) solution of nanometer particle weight-sulfuric acid weight ratio for 24 hr, centrifuging, washing with deionized water for three times, and vacuum drying at 70deg.C to obtain sulfated silica nanometer particle (SiO) ₂ -SO ₃ H)。

Example 8

On the basis of example 2, the shear thickening material was modified with ion-conducting functional groups.

Preparation of a shear thickening material:

SiO ₂ sulfonation: siO is made of ₂ Nanoparticles (Dv 50 of 150 nm) at H ₂ SO ₄ (concentration 99%, siO) ₂ Soaking in 5) solution of nanometer particle weight-sulfuric acid weight ratio for 24 hr, centrifuging, washing with deionized water for three times, and vacuum drying at 70deg.C to obtain sulfated silica nanometer particle (SiO) ₂ -SO ₃ H)；

The shear thickening material modifies the ion-conducting functional groups: (SiO) ₂ Pre-lithiation treatment) to convert SiO ₂ -SO ₃ The H material was immersed in LiOH solution (SiO ₂ -SO ₃ The mass ratio of H to LiOH was 3) for 24 hours. SiO is prepared by heating, washing, drying and other processes ₂ -SO ₃ Li nanoparticles.

Example 9 and example 10

On the basis of example 8, the Dv50 of the shear thickening material was adjusted.

Example 11

The type of shear thickening material was adjusted on the basis of example 8.

Examples 12 and 13.

Based on example 8, the mesoporous pore size of the shear thickening material was adjusted.

Example 14

On the basis of example 8, the separator was replaced with a solid electrolyte membrane.

Preparation of a shear thickening material:

Solid electrolyte membrane: PVDF-HFP was dissolved in 30 times the mass of acetone, stirred for 1 hour until PVDF-HFP was completely dissolved, and then SiO was added to the mixture in an amount equivalent to PVDF-HFP ₂ -SO ₃ Li; then, 2 times of ethanol was added dropwise to the above solution, stirred for 0.5h, the obtained solution was poured onto a rectangular polytetrafluoroethylene mold, and after natural drying, the membrane was further dried in vacuum at 60℃to give a solid electrolyte membrane having a thickness of 100. Mu.m.

Example 15

Based on example 8, the binder in the positive electrode sheet was replaced with polyacrylic acid.

Example 16

On the basis of example 8, the separator surface was not coated with polyvinylidene fluoride.

Comparative example 1

On the basis of example 1, the average aspect ratio of the shear thickening material was adjusted.

Performance testing

Rheological test:

testing the relationship between shear rate and storage modulus (G ') and loss modulus (G' ') obtained by RHE rheometer testing, and recording the phase change shear rate at G' > G '' at a shear rate greater than 1, wherein the smaller the phase change shear rate, the greater the ability of the material to develop shear thickening, and at this time, the phase change shear rate at which the material transitions from shear thinning to shear thickening. The hardness, storage modulus (G'), also known as elastic modulus, is commonly used to characterize a material, and refers to the energy stored by the material during elastic deformation. The loss modulus (G ''), also known as the viscous modulus, refers to the energy lost by a material during viscous deformation, reflecting the viscosity of the material. It is generally believed that when G' > G ", the material will mechanically harden and exhibit shear thickening properties. Conversely, when G ' ' > G ', the material will soften and appear as shear thinning. 200g of iron balls can be used to impact the cell from a height of 100cm (speed 4.5 m/s) to see if the electrolyte can undergo shear thickening.

Drop test

An iron ball with a mass of 200g was dropped from a height of 100cm and hit the experimental soft pack battery, and the voltage after 10min was recorded. Wherein, the voltage is 0, which indicates that the battery is invalid, and the voltage is 4.22V-4.25V, which represents that the battery is normal.

Cycle performance test

Standing the battery for 10min, charging at 25 ℃ to 4.25V at a multiplying power of 1/3C, and ending at a constant voltage of 0.05C; standing for 10min, discharging to 2.8V at 1/3C, standing for 10min, and repeating the above steps to obtain 80% SOH.

Table 1 list of examples

As can be seen from the table, in the comparative examples and comparative examples, the electrolyte is added with the shear thickening material, and the battery has a certain elastic modulus, and can resist external impact.

The foregoing description of the preferred embodiments of the present invention should not be construed as limiting the scope of the invention, but rather as utilizing equivalent structural changes made in the description of the invention and the accompanying drawings, or as directly/indirectly employed in other related technical fields, are included in the scope of the invention.

Claims

1. An electrolyte, characterized in that the electrolyte comprises a shear thickening material having an average aspect ratio in the range of 5 to 100, the shear thickening material comprising a nano-oxide and/or a nano-organic polymer.

2. The electrolyte of claim 1 wherein the average aspect ratio of the shear thickening material ranges from 20 to 100.

3. The electrolyte of claim 1 or 2, wherein the shear thickening material comprises a modified shear thickening material, the modification of the modified shear thickening material comprising an ion-conducting functional group;

the ion-conducting functional group is-SO ₃ Li、-SO ₃ At least one of Na.

4. The electrolyte of claim 1 or 2, wherein the shear thickening material has a Dv50 value in the range of 50nm to 250nm.

5. The electrolyte of claim 1 or 2, wherein the nano-oxide comprises a mesoporous nano-oxide;

and/or, the nano-organic polymer comprises a mesoporous nano-organic polymer.

6. The electrolyte according to claim 1 or 2, wherein the pore size range value of the nano-oxide and/or the nano-organic polymer is 2nm to 20nm;

7. A method for producing the electrolyte according to any one of claims 1 to 6, comprising:

8. An electrolyte comprising a solvent and the electrolyte of any one of claims 1 to 6;

alternatively, the electrolyte comprises a solvent and the electrolyte obtained by the method for producing an electrolyte according to claim 7.

9. The electrolyte of claim 8 wherein the mass of the shear thickening material comprises 20% to 50% by mass of the total mass of the electrolyte.

10. A solid electrolyte comprising the electrolyte of any one of claims 1 to 6.

11. The solid state electrolyte of claim 10, wherein the solid state electrolyte comprises a polymeric substrate and the shear thickening material disposed on the polymeric substrate.

12. The solid state electrolyte of claim 11 wherein the polymeric substrate comprises at least one of polyvinylidene fluoride based polymer, polyethylene glycol based polymer;

and/or the shear thickening material is modified with sulfonic acid groups;

and/or the solid electrolyte has a thickness ranging from 50 μm to 300 μm;

and/or the solid state electrolyte has a porosity of 40% to 60%.

13. A method of producing the solid electrolyte according to any one of claims 10 to 12, comprising:

preparing a shear thickening material;

14. A battery, characterized in that the battery comprises the electrolyte according to any one of claims 1 to 6;

alternatively, the battery comprises the electrolyte obtained by the method for producing an electrolyte according to claim 7;

alternatively, the battery comprises the electrolyte as claimed in claim 8 or 9;

alternatively, the battery comprises the solid electrolyte of any one of claims 10 to 12;

alternatively, the battery comprises the solid electrolyte obtained by the method for producing a solid electrolyte according to claim 13.

15. The battery of claim 14, wherein the battery comprises a positive electrode sheet, a negative electrode sheet, a separator, and an electrolyte, the positive electrode sheet and/or the separator comprising a polyvinylidene fluoride-based polymer, the electrolyte comprising the electrolyte of any one of claims 3 to 6.

16. The battery of claim 15, wherein the positive electrode sheet is disposed adjacent to the separator, a surface of the positive electrode sheet facing the separator comprises polyvinylidene fluoride polymer, and a surface of the separator facing the positive electrode sheet comprises polyvinylidene fluoride polymer.

17. An electrical device comprising a battery as claimed in any one of claims 14 to 16.