Battery cells and their preparation methods, battery devices, power consumption devices and energy storage devices

Abstract

This application relates to the field of batteries, providing a battery cell and its preparation method, a battery device, an electrical device, and an energy storage device. The preparation method of the battery cell includes: providing a cell assembly, wherein the cell assembly is formed by stacking or winding a positive electrode sheet, a separator, and a negative electrode sheet; providing a housing, and placing the cell assembly inside the housing; providing an electrolyte and injecting the electrolyte into the housing; and performing a formation step; wherein the negative electrode sheet includes a current collector, a negative electrode active material, a conductive agent, and a binder, and the binder includes a functional polymer, wherein the functional polymer is formed by chemically bonding a first reaction unit, a second reaction unit, and a third reaction unit to form a molecular network structure. This application can significantly improve the cycle life of the negative electrode, significantly improve the cycle stability and structural integrity of the silicon negative electrode, and provide effective technical support for the practical application of high-capacity lithium-ion batteries.

Description

Technical Field

[0001] This application relates to the field of batteries, and in particular to a battery cell and its preparation method, a battery device, an electrical device, and an energy storage device. Background Technology

[0002] With the increasing demands for battery energy density from mobile electronic devices and electric vehicles, the development of high-capacity anode materials has become a key direction for the development of lithium-ion battery technology. Silicon-based anode materials, due to their ultra-high theoretical specific capacity (4200 mAh·g), are particularly promising. -1 Silicon-based anodes, with their density (approximately 10 times that of graphite) and abundant reserves on Earth, are considered important candidate materials for next-generation lithium-ion battery anodes. Against this backdrop, silicon-based anode technology has become a strategic technology area of ​​focus for the global battery industry.

[0003] Silicon anode materials store lithium ions through a Li-Si alloying reaction, significantly improving the gravimetric and volumetric energy densities of batteries. Compared to the intercalation reaction of traditional graphite anodes, the silicon alloying reaction offers higher lithium storage capacity and faster reaction kinetics. This makes silicon-based anodes suitable not only for high-energy-density applications but also for high-power applications such as fast charging. Summary of the Invention

[0004] This application provides a battery cell and its preparation method, a battery device, an electrical device, and an energy storage device, which at least facilitate the automatic balancing of electrode reactions.

[0005] This application provides a method for preparing a single battery cell, comprising:

[0006] A battery cell assembly is provided, wherein the battery cell assembly is formed by stacking or winding a positive electrode sheet, a separator and a negative electrode sheet;

[0007] A housing is provided to house the battery cell assembly within the housing;

[0008] Provide electrolyte and inject the electrolyte into the housing;

[0009] Perform the formation step;

[0010] The negative electrode sheet includes a current collector, a negative electrode active material, a conductive agent, and a binder. The binder includes a functional polymer. The functional polymer is a molecular network structure formed by chemical bonds connecting a first reaction unit, a second reaction unit, and a third reaction unit. The first reaction unit has lithium ion coordination function, the second reaction unit has mechanical response function, and the third reaction unit has ion conduction function.

[0011] Optionally, the structure of the functional polymer includes a linear triblock structure, a star-shaped multi-arm structure, or a side-linked branch structure.

[0012] Optionally, the first reaction unit has a mass fraction of 30% to 80% in the adhesive, the second reaction unit has a molar fraction of 0.5% to 15% in the adhesive, and the third reaction unit has a mass fraction of 10% to 60% in the adhesive.

[0013] Optionally, the number-average molecular weight of the first reaction unit is 1000 g / mol to 100000 g / mol.

[0014] Optionally, the preparation method of the adhesive includes: stepwise synthesis or one-step copolymerization.

[0015] Optionally, the stepwise synthesis method includes:

[0016] The first reaction unit, the second reaction unit, and the third reaction unit were synthesized respectively.

[0017] The first reaction unit, the second reaction unit, and the third reaction unit are used to synthesize an adhesive through controlled polymerization, stepwise polymerization, click chemistry, or post-functionalization.

[0018] Optionally, the one-step copolymerization method includes:

[0019] Under an inert atmosphere, the first, second, and third reaction units are mixed with an initiator and a chain transfer agent, and a one-step controlled free radical copolymerization reaction is carried out at 40°C to 100°C; or,

[0020] Under an inert atmosphere, the first reaction unit, the second reaction unit, and the third reaction unit are mixed with an initiator and a catalyst, and a one-step controllable free radical copolymerization reaction is carried out at 40℃~100℃.

[0021] Optionally, the first reaction unit comprises a polymer containing an etheroxy group.

[0022] Optionally, the polymer containing ether oxygen groups includes at least one of polyether polymers, polycarbonate polymers, and copolymers, wherein the copolymer is obtained by reacting the polyether polymer and the polycarbonate polymer.

[0023] Optionally, the second reaction unit includes a spiropyran compound.

[0024] Optionally, the spiropyran compounds include at least one of 6-nitrospiro[benzopyran-2,2'-indole], 1,3,3-trimethylspiro[indole-2,3'-naphtho[2,1-b][1,4]thiazine], spiro[benzopyran-2,2'-benzooxazine], spiro[naphthopyran-2,2'-indole], and derivatives containing a spiropyran ring.

[0025] Optionally, the third reaction unit includes an ionic liquid.

[0026] Optionally, the ionic liquid comprises an organic cation group and a paired anion group, wherein the organic cation group includes at least one of imidazolium, pyrrolidineonium, pyridinium, piperidinium, morpholinium, quaternary ammonium, quaternary phosphine, and derivatives of the imidazolium, pyrrolidineonium, pyridinium, piperidinium, morpholinium, quaternary ammonium, and quaternary phosphine; and the paired anion group includes at least one of bis(trifluoromethanesulfonyl)imide, bis(fluorosulfonyl)imide, bis(pentafluoroethylsulfonyl)imide, hexafluorophosphate, tetrafluoroboric acid, and trifluoromethanesulfonic acid.

[0027] Optionally, the controlled polymerization method includes atom transfer radical polymerization or reversible addition-fragmentation chain transfer polymerization.

[0028] Optionally, the atom transfer radical polymerization method includes:

[0029] The first reaction unit, the second reaction unit, and the third reaction unit are dissolved in a solvent, an initiator and a catalyst are added, and the reaction is carried out in an inert atmosphere at 40°C to 100°C.

[0030] Optionally, the amount of the initiator is 0.1% to 2% of the total molar number of the first reaction unit, the second reaction unit, and the third reaction unit, and the amount of the catalyst is 1 to 5 times the amount of the initiator.

[0031] Optionally, the polymerization reaction is an atom transfer radical polymerization, the initiator includes a brominated alkyl initiator, and the catalyst includes a Cu(I) / ligand catalyst; the polymerization reaction is a reversible addition-fragmentation chain transfer polymerization, and the initiator includes at least one of an azo initiator and a dithioester chain transfer agent.

[0032] Optionally, the adhesive may also include additives.

[0033] Optionally, the additive includes at least one of an interface enhancer, a crosslinking regulator, and a stabilizer, wherein the amount of the interface enhancer is 0.1% to 5% of the total mass of the adhesive, the amount of the crosslinking regulator is 0.1% to 10% of the total mass of the adhesive, and the amount of the stabilizer is 0.01% to 2% of the total mass of the adhesive.

[0034] Optionally, the interface enhancer includes at least one of silane coupling agents and titanate coupling agents; the crosslinking regulator includes at least one of diacrylates and triacrylates; and the stabilizer includes at least one of antioxidants and heat stabilizers.

[0035] Optionally, the negative electrode active material includes a silicon-based active material.

[0036] Optionally, the silicon-based active material includes at least one of nano-silicon powder, micro-silicon powder, silicon-carbon composite material, silicon monoxide, silicon nanowires, and porous silicon.

[0037] Optionally, the formation step includes performing an initial charge-discharge cycle at a rate of 0.05C to 0.2C.

[0038] This application also provides a battery cell obtained by the above-described preparation method.

[0039] This application also provides a battery device, including the battery cell as described above, wherein the battery device includes one or more of the following: battery module, battery pack, and energy storage battery.

[0040] In another aspect, this application provides an electrical device that includes a battery device as described above, the battery device being used to provide electrical energy.

[0041] Another aspect of this application provides an energy storage device, which includes a battery device as described above, the battery device being used to store electrical energy.

[0042] The energy storage device includes a battery pack, which in turn includes multiple batteries, an energy management system (EMS), a battery management system (BMS), and a power storage converter (PCS). The electrical devices include vehicles, household appliances, electric motors, medical equipment, scientific instruments, and power grids.

[0043] The technical solution provided in this application has at least the following advantages:

[0044] This application proposes a "mechanically responsive ion-gated" binder technology based on the concept of biomimetic intelligent response. The core of this solution lies in integrating mechanical sensing, signal transduction, and ion regulation functions into a single molecular system. Through the mechanochromic mechanism of spiropyran molecular switching, real-time monitoring and active regulation of the silicon anode lithiation process are achieved. This facilitates the realization of high-capacity battery cells and is suitable for long-term energy storage applications, such as energy storage systems that can operate continuously for 4 to 8 hours at rated power.

[0045] Compared to the passive adaptation strategy of conventional technologies, this application adopts an innovative concept of active intervention, upgrading the binder from a simple mechanical support material into a "smart manager" with sensing and regulation functions. This transformation enables the binder to sense the stress distribution state inside the electrode in real time and adjust the ion transport impedance of different regions accordingly. Through a negative feedback mechanism, it guides lithium ions to flow to areas with lower stress, thereby achieving automatic balancing of the electrode reaction.

[0046] The ingenious aspect of this application lies in establishing a molecular-scale force-electric coupling mechanism. Under mechanical stretching, the spiropyran molecule undergoes a ring-opening reaction, resulting in significant changes in its molecular dipole moment and electronegativity, leading to its dependence on Li... + The coordination ability decreases, and the local ionic conductivity decreases accordingly. This molecular-scale response mechanism ensures the precision and real-time nature of regulation, avoiding the lag and inhomogeneity problems of macroscopic response systems.

[0047] Compared with traditional binders (such as PAA), this application can significantly improve the cycle life of silicon anodes, significantly improve the cycle stability and structural integrity of silicon anodes, and provide effective technical support for the practical application of high-capacity lithium-ion batteries. Attached Figure Description

[0048] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 The flowchart corresponds to the method for preparing a single battery cell provided in the embodiments of this application. Detailed Implementation

[0050] As the background technology indicates, the development of silicon-based anode technology has moved from the early proof-of-concept stage to the engineering application stage. However, the significant volume change characteristic of silicon anodes remains a core technological challenge restricting their commercial application. During charging and discharging, the alloying / dealloying reaction between silicon and lithium leads to a volume change of over 300%, which severely impacts the mechanical stability and electrochemical performance of the electrode. Therefore, developing advanced binder technologies that can effectively manage the volume change of silicon anodes has become a key technological bottleneck for realizing the industrial application of silicon-based anodes.

[0051] Currently, the binder technologies used for silicon-based anodes mainly include traditional polymer binders, self-healing binders, and conductive binders. Traditional polymer binders are represented by polyacrylic acid (PAA) and polyimide (PI). These binders provide mechanical bonding by forming hydrogen bonds or chemical bonds with the oxide layer on the surface of silicon particles through functional groups such as carboxyl and amide groups. Their working principle is to form a flexible polymer network around the silicon particles, which adapts to the volume changes of the silicon particles through the extension and deformation of the polymer chains.

[0052] Self-healing adhesives are a novel technological approach developed in recent years, primarily based on supramolecular interactions or dynamic covalent bonding mechanisms. Typical examples include polymers containing hydrogen bonds (such as polyurethane), aromatic polymers containing π-π stacked units, and polymers containing dynamic sulfur bonds. These adhesives work by utilizing the reversibility of weak interactions; when the adhesive network breaks due to stress, it can spontaneously repair itself through molecular rearrangement, thereby maintaining the integrity of the electrode structure.

[0053] Conductive binder technology aims to provide both mechanical support and electronic conductivity. Representative materials include conductive polymers such as polyaniline (PANI) and poly(3,4-ethylenedioxythiophene) (PEDOT), as well as polymer-carbon nanotube composite systems. These binders establish continuous electron transport paths while providing mechanical bonding by introducing conjugated structures or conductive fillers into the polymer backbone or side chains, reducing the need for additional conductive agents.

[0054] While the aforementioned technologies have improved the cycle stability of silicon anodes to some extent, they still have fundamental limitations. First, traditional polymer binders face a dilemma of balancing mechanical and electrochemical properties. To provide sufficient mechanical strength to confine silicon particles, the crosslinking density and content of the binder need to be increased, but this leads to decreased electrode flexibility and increased ion transport impedance. Simultaneously, even the most flexible polymer binders cannot perfectly match the elongation of the silicon anode, which exceeds 300% in volume change, inevitably leading to fatigue fracture during repeated cycling.

[0055] Secondly, while self-healing adhesives possess damage repair capabilities, their self-healing process typically requires external stimulation (such as heating or solvent treatment) or a considerable amount of time to complete, making it impossible to achieve a rapid response under the actual operating conditions of a battery. More importantly, the self-healing mechanism is based on the random rearrangement of molecular chains, lacking directionality and selectivity, and thus cannot provide differentiated treatment for the stress states of different regions.

[0056] Furthermore, while conductive binders can improve the electronic conductivity of electrodes, the conductive network is prone to breakage and reconstruction during the volume change of the silicon anode, leading to unstable resistance. Simultaneously, the introduction of conductive components often reduces the mechanical properties of the binder, necessitating a trade-off between conductivity and mechanical performance.

[0057] The fundamental problem lies in the fact that related technologies all employ a passive response strategy, only able to adaptively adjust after the silicon particles undergo volume changes, unable to actively intervene in and control the volume change process. This passive mode leads to uneven reactions in the silicon anode during cycling, with some areas over-expanding while others react insufficiently, creating a "Matthew effect" and ultimately causing the overall failure of the electrode structure. Therefore, there is an urgent need to develop binder technologies with active control capabilities to achieve precise management of the silicon anode reaction process.

[0058] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0059] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0060] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0061] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0062] According to some embodiments of this application, one embodiment of this application provides a method for preparing a single battery cell, such as... Figure 1 As shown, it includes:

[0063] S1. Provide battery cell assembly, which is composed of positive electrode sheet, separator and negative electrode sheet stacked or wound together;

[0064] S2. Provide a housing to place the battery cell assembly inside the housing;

[0065] S3. Provide electrolyte and inject the electrolyte into the casing;

[0066] S4. Perform the formation step;

[0067] The negative electrode sheet includes a current collector, a negative electrode active material, a conductive agent, and a binder. The binder includes a functional polymer. The functional polymer is a molecular network structure formed by chemical bonds connecting a first reaction unit, a second reaction unit, and a third reaction unit. The first reaction unit has lithium ion coordination function, the second reaction unit has mechanical response function, and the third reaction unit has ion conduction function.

[0068] Based on the concept of biomimetic intelligent response, this application proposes a "mechanically responsive ion-gated" binder technology. The core of this solution lies in integrating mechanical sensing, signal transduction, and ion regulation functions into a single molecular system. Through the mechanochromic mechanism of spiropyran molecular switches, real-time monitoring and active control of the lithiation process of silicon anodes are achieved.

[0069] Compared to the usual passive adaptation strategy, this application adopts an innovative concept of active intervention, upgrading the binder from a simple mechanical support material into a "smart manager" with sensing and regulation functions. This transformation enables the binder to sense the stress distribution state inside the electrode in real time and adjust the ion transport impedance of different regions accordingly. Through a negative feedback mechanism, it guides lithium ions to flow to areas with lower stress, thereby achieving automatic balancing of the electrode reaction.

[0070] The ingenious aspect of this application lies in establishing a molecular-scale force-electric coupling mechanism (i.e., a quantitative relationship between strain and conductivity). Spiropyran molecules undergo a ring-opening reaction under mechanical stretching, resulting in significant changes in their molecular dipole moment and electronegativity, leading to changes in their dependence on Li. + The coordination ability decreases, and the local ionic conductivity decreases accordingly. This molecular-scale response mechanism ensures the precision and real-time nature of regulation, avoiding the lag and inhomogeneity problems of macroscopic response systems.

[0071] Compared to traditional binders (such as PAA), this application significantly improves the cycle life of silicon anodes, substantially enhancing their cycle stability and structural integrity, thus providing effective technical support for the practical application of high-capacity lithium-ion batteries. It facilitates the realization of high-capacity rechargeable batteries and is suitable for long-term energy storage applications, such as energy storage systems that can operate continuously for 4 to 8 hours at rated power.

[0072] Silicon anode binder technology is primarily based on a "passive adaptation" design philosophy. It adapts to volume changes in the silicon anode by improving the binder's mechanical strength, flexibility, or self-healing ability; essentially, it remains a passive response strategy. Representative technologies include polyacrylic acid (PAA) modified binders, which enhance adhesion to the silicon surface through improved chemical bonding; polyionic liquid binders, which adapt to volume changes by increasing flexibility; and self-healing binders, which achieve damage repair through supramolecular interactions.

[0073] This application proposes for the first time the "active control design concept," which achieves real-time monitoring and active intervention in the lithiation process of silicon anodes through an integrated mechanical response ion gating mechanism. This paradigm shift from "passive adaptation" to "active control" upgrades binders from simple mechanical support materials to "intelligent managers" with sensing and control functions, representing a new direction in binder technology development.

[0074] Typically, response mechanisms are based on macroscopic or mesoscopic physical processes, such as the dynamic equilibrium of supramolecular interactions and conformational changes of polymer chain segments. These mechanisms tend to be relatively slow and have limited precision.

[0075] This application establishes a molecular-scale mechano-electric coupling response mechanism. Through the ring-closed to ring-opening conformational transition of spiropyran molecules, a rearrangement of the local polar environment is induced, achieving coupled regulation of mechanical response and ion conduction properties. This molecular-scale response ensures real-time and precise regulation, with response times reaching the millisecond level, far faster than traditional supramolecular self-healing mechanisms (minutes to hours). Simultaneously, the uniform distribution at the molecular scale guarantees spatial consistency of the response, avoiding the local inhomogeneities that may exist in macroscopic response systems.

[0076] Even when traditional adhesives possess self-healing capabilities, their repair process is typically random and non-directional, failing to provide differentiated treatment for stress states in different areas. While some studies have focused on the inhomogeneity of reactions within electrodes, effective active control methods are lacking.

[0077] This application achieves intelligent guidance of lithium-ion flow through a negative feedback mechanism of "increased stress - decreased conductivity". When a region experiences high stress due to over-lithiation, the ionic conductivity of that region automatically decreases, guiding lithium ions to the low-stress region, thereby spontaneously achieving reaction equilibrium. This negative feedback self-regulation mechanism mimics the intelligent regulatory characteristics of biological systems, introducing a biomimetic intelligent concept into electrochemical systems.

[0078] Composite adhesives typically employ multi-component physical compounding methods, such as blending PAA with polyionic liquids or combining conductive polymers with traditional adhesives. This physical compounding approach is prone to problems like phase separation and poor interfacial compatibility, and lacks organic coordination between the functions of the various components.

[0079] This application employs a chemically bonded triblock copolymer design to integrate mechanosensing, ion conduction, and lithium-ion coordination functions into a single macromolecule. The chemical bonding ensures the spatial correlation and synergistic response of each functional unit, avoiding phase separation issues. Furthermore, precise molecular design enables synergistic optimization among the functional units, such as matching the spiropyran content with the ionic liquid (IL) content, and matching the response threshold with the strain window of the silicon anode.

[0080] The repair process of self-healing adhesives usually requires external stimulation (such as heating or solvent treatment) or a long time to complete, and the number of repairs is limited. They are prone to fatigue decay in repeated cycles.

[0081] The closed-ring-open-ring transition of spiropyran in this application exhibits excellent reversibility; the open-ring state can spontaneously recover to the closed-ring state through thermal relaxation or light exposure, without external excitation. Literature reports that spiropyran can achieve reversible cycle counts of up to 10-1. 6 More than 100 cycles, far exceeding the actual cycle requirements of batteries. This inherent reversible property ensures the functional stability of the binder during long-term cycling.

[0082] High-performance binders often require special preparation processes or harsh usage conditions, such as high-temperature treatment, special solvent systems, and complex multi-step preparation, which increases the difficulty and cost of industrialization.

[0083] The binder in this application is prepared based on mature polymerization technology with mild process conditions, fully compatible with existing electrode fabrication processes. The binder can be used in common solvents, and the dosage is comparable to that of traditional binders, without significantly increasing battery costs. Furthermore, the intelligent control function is an intrinsic property of the material, requiring no additional control system or external excitation, thus demonstrating good practicality.

[0084] Traditional binder technologies are often optimized for specific electrode materials or battery systems, and their application scope is relatively limited.

[0085] The intelligent response mechanism of this application is universal, and can be matched to the strain characteristics of different anode materials by adjusting the type, content, and substituents of spiropyran. It can be adapted to different electrolyte systems by changing the ionic liquid composition. Furthermore, it can be extended to other battery systems such as sodium-ion batteries and potassium-ion batteries by modifying the coordination unit. This technological extensibility provides broad prospects for the development of binders in multiple application fields.

[0086] This "strain-conductivity quantitative relationship" is achieved through the second reaction unit in the binder. The core mechanism lies in the following: when the silicon anode experiences localized mechanical strain due to lithium intercalation expansion, this strain acts on the binder molecular chain, causing a reversible conformational transition of the spiropyran unit from a closed-ring to an open-ring structure (merocyanine structure). The electronegativity and molecular dipole moment of the ring-opening structure are significantly enhanced, forming a more stable complex with lithium ions. This increases the migration resistance of lithium ions in this micro-region, macroscopically manifesting as a significant decrease in local ionic conductivity. This forms a negative feedback regulation of "increased stress - decreased conductivity," meaning the greater the mechanical strain (ε), the lower the local ionic conductivity (σ). The specific formula is as follows:

[0087] σ(ε)= σ 0 ×exp[-kgate ×(ε-ε th )] (when ε>ε th );

[0088] σ(ε)=σ 0 (when ε ≤ ε th ).

[0089] in:

[0090] σ(ε): Local ionic conductivity (mS / cm) at strain ε;

[0091] σ0: Basic ionic conductivity without strain (mS / cm);

[0092] k gate The gate coefficient (dimensionless) is defined as the rate of change of relative conductivity caused by a unit strain.

[0093] ε: Local mechanical strain (0~1, dimensionless);

[0094] ε th Response threshold, defined as the strain value corresponding to a 10% decrease in conductivity.

[0095] Optionally, the cathode material system can employ various lithium-ion battery cathode materials, including layered oxides, spinel structures, polyanionic compounds, and lithium-rich manganese-based cathode materials. Layered oxide cathode materials include ternary materials such as LiNi. x Co y Mn z O2(NCM), LiNi x Co y Al z O2(NCA), LiCoO2, etc., where the values ​​of x, y, and z range from 0.1 to 0.9, 0.05 to 0.4, and 0.05 to 0.4, respectively, and x + y + z = 1. Spinel-structured cathode materials include LiMn2O4 and LiNi. 0.5 Mn 1.5 O4, etc. Polyanionic cathode materials include LiFePO4, LiMnPO4, Li3V2(PO4)3, etc. Lithium-rich manganese-based cathode materials include the xLi2MnO3·(1-x)LiMO2 system, where M is a transition metal such as Ni, Co, Mn, etc., and x ranges from 0.1 to 0.7.

[0096] Optionally, the positive electrode formulation includes 85wt%~95wt% positive electrode active material, 2wt%~8wt% conductive agent, and 2wt%~8wt% binder. Conductive agents can be selected from carbon black, acetylene black, carbon nanotubes, graphene, etc. Binders can be selected from polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), polytetrafluoroethylene (PTFE), etc. The positive electrode current collector uses aluminum foil with a thickness of 10μm~25μm, or carbon-coated aluminum foil.

[0097] Optionally, the positive electrode can be prepared using conventional methods, which involves mixing the positive electrode active material, conductive agent, and binder according to the formula ratio to form a slurry, coating it onto an aluminum foil current collector, and then drying and rolling it to form a positive electrode sheet.

[0098] The negative electrode active material can be a silicon-based active material, specifically nano-silicon powder, micron-silicon powder, silicon-carbon composite material, or silicon monoxide (SiO2). x The anode material can be selected from silicon nanowires, porous silicon, etc., with a silicon content of 50wt%~90wt% and a carbon content of 10wt%~50wt%. The anode formulation includes 70wt%~95wt% silicon-based active material, 2wt%~20wt% conductive agent, and 2wt%~20wt% binder. Conductive agents can be carbon black, graphite, carbon nanotubes, etc. All components are weight percentages, and the sum of all components is 100wt% based on the solid portion of the electrode. The anode current collector uses copper foil with a thickness of 6μm~20μm.

[0099] Optionally, the negative electrode slurry preparation employs a multi-step mixing process. First, the binder is dissolved in a suitable solvent, such as deionized water, N-methylpyrrolidone (NMP), acetone, or ethanol. The binder concentration is controlled at 5wt%–20wt%. Then, a conductive agent is added, and the mixture is dispersed at high speed or ultrasonically for 5–30 minutes to form a conductive network. Finally, silicon-based active materials are added, and the mixture is stirred using a planetary mixer at 200–2000 rpm for 2–12 hours. The resulting negative electrode slurry has a solid content controlled at 40wt%–80wt% and a viscosity controlled at 2000 Pa·s–15000 mPa·s. The slurry is coated onto a copper foil current collector using a coating machine. The coating thickness is determined based on the areal density requirements, typically a wet film thickness of 100 μm–500 μm. After coating, the slurry is dried at 80℃–120℃ for 10–120 minutes. After drying, it is rolled to a compaction density of 1.2 g / cm³. 3 ~2.0g / cm 3 .

[0100] Membrane materials can be selected from polyolefin membranes, ceramic-coated membranes, polymer membranes, etc. Polyolefin membranes include polypropylene (PP), polyethylene (PE), PP / PE / PP three-layer composite membranes, etc., with a thickness of 12μm~25μm. Ceramic-coated membranes have ceramic particles such as Al2O3, SiO2, and TiO2 coated on the surface of the polyolefin substrate, with a coating thickness of 1μm~5μm.

[0101] The electrolyte system can use organic electrolytes such as carbonates and ethers. Solvents can be selected from single or mixed systems of ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), 1,2-dimethoxyethane (DME), and 1,3-dioxane (DOL). Lithium salts can be selected from LiPF6, LiTFSI, LiFSI, LiBF4, and LiClO4, with concentrations ranging from 0.8M to 1.5M. Functional additives such as vinylene carbonate (VC), fluoroethylene carbonate (FEC), succinate (SN), and 1,3-propanesulfonate lactone (PS) can be added.

[0102] Optionally, the assembly of individual battery cells is carried out in a dry environment with the ambient humidity controlled below 1%. The positive electrode, separator, and negative electrode are stacked or wound sequentially to form a cell assembly. The cell assembly is then installed into the battery casing, and electrolyte is injected. The amount of electrolyte injected is determined based on the battery design capacity and cell porosity, typically 1.1 to 1.3 times the theoretical amount.

[0103] After electrolyte filling, the batteries undergo vacuum impregnation to remove air from the cells and ensure thorough electrolyte wetting. Then, pre-charge formation is performed using a small current (0.05C~0.2C) for the first charge and discharge cycle to activate the electrode materials and establish a stable solid electrolyte interphase (SEI) film. The formed batteries are then subjected to capacity testing to select qualified products.

[0104] The preparation process described in this application has good industrial applicability. The binder synthesis process is based on mature polymerization technology, the raw materials are readily available, and the equipment requirements are not high. The electrode preparation process is compatible with existing lithium-ion battery production lines and does not require large-scale equipment modifications. The binder dosage is moderate and will not significantly increase battery costs.

[0105] Key control points in the process include temperature and time control of the polymerization reaction, uniformity control of slurry mixing, and optimization of coating and drying process parameters. Establishing a comprehensive process control system and quality management system ensures product consistency and reliability.

[0106] Optionally, the structure of the functional polymer includes a linear triblock structure, a star-shaped multi-arm structure, or a side-linked branch structure.

[0107] Linear triblock structures, arranged in a sequence of "coordination unit-gating unit-conduction unit," offer advantages such as relatively simple synthesis and controllable molecular weight distribution. Star-shaped multi-arm structures, with functional crosslinking points at their core, radiate outwards to connect multiple functional segments, achieving higher functional density. Side-linked graft structures use one functional unit as the main backbone, grafting other functional units as side chains, offering flexible structural design.

[0108] Optionally, the mass fraction of the first reaction unit in the adhesive is 30% to 80%, specifically 30%, 40%, 50%, 60%, 65%, 70%, or 80%; the molar fraction of the second reaction unit in the adhesive is 0.5% to 15%, specifically 0.5%, 1%, 2%, 3%, 5%, 7%, 8%, 10%, 12%, or 15%; and the mass fraction of the third reaction unit in the adhesive is 10% to 60%, specifically 10%, 20%, 25%, 30%, 40%, 50%, or 60%.

[0109] Optionally, the number-average molecular weight of the first reaction unit is 1000 g / mol to 100000 g / mol, specifically 1000 g / mol, 2000 g / mol, 5000 g / mol, 8000 g / mol, 10000 g / mol, 20000 g / mol, 30000 g / mol, 40000 g / mol, 50000 g / mol, 60000 g / mol, 80000 g / mol, or 100000 g / mol.

[0110] Optionally, the preparation method of the adhesive includes: stepwise synthesis or one-step copolymerization.

[0111] Optionally, the stepwise synthesis method includes:

[0112] The first reaction unit, the second reaction unit, and the third reaction unit were synthesized respectively.

[0113] The first reaction unit, the second reaction unit, and the third reaction unit are used to synthesize an adhesive through controlled polymerization, stepwise polymerization, click chemistry, or post-functionalization.

[0114] Optionally, the stepwise polymerization method specifically includes the following steps: first synthesizing hydroxyl-terminated polyether segments, reacting them with isocyanate-containing spiropyran derivatives at 60℃~80℃ for 12h~24h, and finally coupling them with ionic liquid units.

[0115] Optionally, the click chemistry method specifically includes the following steps: using an azide-alkynyl cycloaddition reaction (CuAAC), catalyzed by Cu(I), and reacting at room temperature for 4-8 hours.

[0116] Optionally, the post-functionalization method includes the following steps: first synthesizing a copolymer backbone containing active groups, and then introducing functional groups through a grafting reaction.

[0117] Optionally, the one-step copolymerization method includes:

[0118] Under an inert atmosphere, the first, second, and third reaction units are mixed with an initiator and a chain transfer agent, and a one-step controlled free radical copolymerization reaction is carried out at 40°C to 100°C; or,

[0119] Under an inert atmosphere, the first reaction unit, the second reaction unit, and the third reaction unit are mixed with an initiator and a catalyst, and a one-step controllable free radical copolymerization reaction is carried out at 40℃~100℃.

[0120] Optionally, the first reaction unit comprises a polymer containing ether-oxygen groups. As a basic functional module of the binder, it primarily provides a solvation environment for lithium ions, flexible mechanical support, and basic ion transport channels.

[0121] Optionally, the polymer containing ether oxygen groups includes at least one of polyether polymers, polycarbonate polymers, and copolymers, wherein the copolymer is obtained by reacting the polyether polymer and the polycarbonate polymer.

[0122] Optionally, the polyether polymers include polyethylene oxide, polypropylene oxide, polytetrahydrofuran, polyoxymethylene, etc., and the polycarbonate polymers include polyvinyl carbonate, polypropylene carbonate, or their random copolymers, graft copolymers and block copolymers, wherein the polyethylene oxide segment provides lithium-ion coordination sites, and the polypropylene oxide segment provides mechanical strength and inhibits crystallization.

[0123] Optionally, the first reaction unit may be a commercially available polyethylene glycol methacrylate (PEGMA), polyethylene glycol dimethacrylate (PEGDMA), or prepared by esterification of terminal hydroxyl polyether with methacryloyl chloride under alkaline conditions.

[0124] Optionally, the second reaction unit includes a spiropyran compound, which is responsible for sensing changes in local stress of the electrode and adjusting the ion conduction performance of that region accordingly.

[0125] Spiropyran compounds undergo a reversible ring-closed to ring-opening conformational transition under mechanical stress. The resulting merocyanine (MC) structure exhibits a significantly increased molecular dipole moment and electron cloud distribution, leading to a rearrangement of local polar and coordination environments and consequently altering the ion conductivity of this microregion. The MC structure is similar to that of Li... + The formation of more stable complexes leads to Li +The increased desolvation energy barrier, elevated migration activation energy, and decreased mobility of Li result in a decrease in local ionic conductivity. Due to the formation of a conductivity gradient within the electrode, Li... + It spontaneously flows to the low-resistance, low-stress region, achieving negative feedback control of the lithiation process.

[0126] Optionally, spiropyran compounds include at least one of 6-nitrospiro[benzopyran-2,2'-indole], 1,3,3-trimethylspiro[indole-2,3'-naphtho[2,1-b][1,4]thiazine], spiro[benzopyran-2,2'-benzoxazine], spiro[naphthopyran-2,2'-indole], and derivatives containing a spiropyran ring. Among these, 6-nitrospiro[benzopyran-2,2'-indole] compounds are particularly advantageous due to their moderate mechanical response threshold and excellent ring-opening-ring-closing reversibility at room temperature. Substituents can be selected from electron donor or acceptor groups such as nitro, cyano, carboxyl, methoxy, ethoxy, methyl, ethyl, fluorine, chlorine, and bromine, used to adjust the mechanical response sensitivity and ring-opening threshold of the spiropyran. Among them, the benzopyran ring can be substituted at the 5', 7', and 8' positions, and the indole ring can be substituted at the N atom (1 position), 5 position, and 7 position.

[0127] Optionally, the second reaction unit can be prepared by coupling spiropyran with polymerizable groups. Taking 6-nitrospiro[benzopyran-2,2'-indole] as an example, acrylic, methacrylic, or vinyl groups can be introduced into the spiropyran molecule through esterification, etherification, or amidation reactions. The reaction temperature is controlled at 20℃~80℃, and the reaction time is 4h~24h.

[0128] Optionally, the third reaction unit may include an ionic liquid.

[0129] The third reaction unit provides the binder with significantly enhanced ionic conductivity and excellent electrochemical stability, which is key to achieving high-rate performance.

[0130] Optionally, the ionic liquid comprises an organic cation group and a paired anion group. The organic cation group includes at least one of imidazolium, pyrrolidineonium, pyridinium, piperidinium, morpholinium, quaternary ammonium, quaternary phosphine, and derivatives of imidazolium, pyrrolidineonium, pyridinium, piperidinium, morpholinium, quaternary ammonium, and quaternary phosphine. The paired anion group includes at least one of bis(trifluoromethanesulfonyl)imide, bis(fluorosulfonyl)imide, bis(pentafluoroethylsulfonyl)imide, hexafluorophosphate, tetrafluoroboric acid, and trifluoromethanesulfonic acid.

[0131] Optionally, the preparation of the third reaction unit is achieved through an ion exchange reaction between an ionic liquid cation and a polymerizable anion or a polymerizable cation. Taking 1-methyl-3-ethylimidazolium as an example, 1-methyl-3-vinylimidazolium TFSI or imidazolium salts containing acrylic acid groups can be prepared.

[0132] Compared to pure polyether systems, polyionic liquid segments can increase room temperature ionic conductivity by 1 to 2 orders of magnitude.

[0133] Optionally, the controlled polymerization method includes atom transfer radical polymerization or reversible addition-fragmentation chain transfer polymerization.

[0134] Optionally, the atom transfer radical polymerization method includes:

[0135] The first reaction unit, the second reaction unit, and the third reaction unit are dissolved in a solvent, an initiator and a catalyst are added, and the reaction is carried out in an inert atmosphere at 40°C to 100°C.

[0136] Optionally, the amount of the initiator is 0.1% to 2% of the total molar number of the first reaction unit, the second reaction unit, and the third reaction unit, and the amount of the catalyst is 1 to 5 times the amount of the initiator.

[0137] Optionally, the reversible addition-fragmentation chain transfer polymerization method includes:

[0138] The first reaction unit, the second reaction unit, and the third reaction unit are dissolved in a solvent, and an initiator and a chain transfer agent are added. The reaction is carried out in an inert atmosphere at 40°C to 100°C.

[0139] Optionally, the amount of the chain transfer agent is 0.1% to 5% of the total moles of the first reaction unit, the second reaction unit, and the third reaction unit.

[0140] Optionally, the polymerization reaction is an atom transfer radical polymerization, the initiator includes a brominated alkyl initiator, and the catalyst includes a Cu(I) / ligand catalyst, such as Cu(I)Br / 2,2'-bipyridine or Cu(I)Br / PMDETA ligand system; the polymerization reaction is a reversible addition-fragmentation chain transfer polymerization, the initiator includes an azo initiator, and the chain transfer agent includes a dithioester chain transfer agent.

[0141] Optionally, the brominated alkyl initiator includes at least one of ethyl 2-bromoisobutyrate and methyl α-bromoisobutyrate; the Cu(I) / ligand catalyst includes at least one of Cu(I)Br / 2,2'-bipyridine or Cu(I)Br / PMDETA ligand system; the azo initiator includes at least one of azobisisobutyronitrile and azobisisoheptanenitrile; and the dithioester chain transfer agent includes at least one of dithiobenzoate, dithiocarbonate, and xanthate.

[0142] Optionally, the adhesive may also include additives.

[0143] Optionally, the additive includes at least one of an interface reinforcing agent, a crosslinking regulator, and a stabilizer. The amount of the interface reinforcing agent is 0.1% to 5% of the total mass of the binder, specifically 0.1%, 0.3%, 0.5%, 0.8%, 1%, 3%, or 5%. The amount of the crosslinking regulator is 0.1% to 10% of the total mass of the binder, specifically 0.1%, 0.3%, 0.5%, 0.8%, 1%, 3%, 5%, 7%, 8%, or 10%. The amount of the stabilizer is 0.01% to 2% of the total mass of the binder, specifically 0.01%, 0.3%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.7%, 1.8%, or 2%.

[0144] Optionally, the interface enhancer includes at least one of silane coupling agents and titanate coupling agents; the crosslinking regulator includes at least one of diacrylates and triacrylates; and the stabilizer includes at least one of antioxidants and heat stabilizers.

[0145] Optionally, the negative electrode active material includes a silicon-based active material.

[0146] Optionally, the negative electrode active material includes at least one of nano-silicon powder, micro-silicon powder, silicon-carbon composite material, silicon monoxide, silicon nanowires, and porous silicon.

[0147] Optionally, the formation step includes: performing an initial charge and discharge at a rate of 0.05C to 0.2C, specifically at rates of 0.05C, 0.07C, 0.09C, 0.1C, 0.12C, 0.14C, 0.16C, 0.18C, or 0.2C.

[0148] Optionally, the formation process is performed at 25°C. It can be controlled by a program (rather than a fixed duration) and mainly includes two stages: first, two charge-discharge cycles at a 0.05C rate, followed by one cycle at a 0.1C rate. The charging stage involves constant current to 4.2V, then switching to constant voltage until the current drops to 0.01C (cutoff). The discharging stage involves constant current to 2.8V.

[0149] This application also provides a battery cell obtained by the above-described preparation method.

[0150] This application also provides a battery device, including the battery cell as described above, wherein the battery device includes one or more of the following: battery module, battery pack, and energy storage battery.

[0151] In another aspect, this application provides an electrical device that includes a battery device as described above, the battery device being used to provide electrical energy.

[0152] Another aspect of this application provides an energy storage device, which includes a battery device as described above, the battery device being used to store electrical energy.

[0153] The working principle of the binder in this application is based on a multi-level linkage mechanism of "mechanical stimulation - molecular conformational change - ion conduction regulation - negative feedback current introduction". When a certain region of the electrode generates large mechanical stress due to excessive lithium ion insertion, the binder molecular chain in that region is subjected to corresponding tensile strain. Under the action of mechanical force exceeding its response threshold, the spiropyran unit undergoes a molecular conformational transformation from a closed-ring configuration to an open-ring configuration.

[0154] The closed-ring spiropyran exists as a colorless sp form with a relatively small molecular dipole moment. Under sufficient mechanical stress, the spiropyran molecule undergoes CO bond breakage, forming a highly conjugated open-ring merocyanine (MC) structure. This structure exhibits a significantly increased molecular dipole moment and stronger coordination ability. The ring-opening merocyanine structure alters the local polar environment and solvation structure, changing the lithium-ion conduction kinetics in this region, manifested as a relative decrease in local ionic conductivity.

[0155] This negative feedback regulation mechanism of "increased stress - decreased conductivity" makes lithium ions more inclined to migrate to areas with lower stress, thereby spontaneously balancing the degree of lithiation inside the electrode and effectively suppressing the Matthew effect of "the rich get richer". As the stress redistributes, the open-ring cyanine structure can return to the closed-ring state through thermal relaxation or light exposure, restoring its original ion conduction characteristics and completing the response-regulation-recovery cycle.

[0156] To verify the technical effectiveness of the mechanically responsive ion-gated binder proposed in this application in improving the cycle stability, rate performance, and volume change control of silicon-based anodes, a series of embodiments and comparative examples were designed. The experimental design followed a three-layer progressive logic of "core verification layer → parameter optimization layer → application expansion layer," systematically exploring the effects of spiropyran-gated units, ionic liquid conduction units, polyether coordination units, and self-healing units on binder performance and overall battery performance.

[0157] The core verification layer (Example 1 and Comparative Examples 1 to 5) aims to verify the necessity and synergistic effect of each functional unit in the triblock copolymer structure through systematic comparison of key components, especially the effectiveness of the spiropyran-gated unit in achieving the "stress increase - conductivity decrease" negative feedback control mechanism, and the technical advantages of chemical bonding over physical mixing.

[0158] The parameter optimization layer (Examples 2 to 13) explores the influence of various parameters on gating sensitivity, ionic conductivity, mechanical properties and cycle stability by systematically controlling the content and type of spiropyran, the content and type of ionic liquid and anion, the molecular weight of polyether, the molecular topology and the introduction of self-healing units, and determines the optimal component ratio and structural design.

[0159] Based on the optimal formulation, the application extension layer (Examples 14-20) was used to verify the effect of the binder on different silicon-based materials (nano-silicon, SiO2). x The applicability of the data, as well as its performance in practical application scenarios such as high areal density, extreme temperature, high rate of increase and long cycle, provides data support for industrial applications.

[0160] The raw materials and formulations used in each embodiment and comparative example are shown in Tables 1-1, 1-2 and 1-3.

[0161] Example 1

[0162] This embodiment provides a method for preparing a single battery cell (3.8A stacked soft-pack full cell, single-layer stacked), including the following steps:

[0163] S1. Provide a battery cell assembly, wherein the battery cell assembly is formed by stacking or winding a positive electrode sheet, a separator and a negative electrode sheet;

[0164] S2. Provide a housing and place the battery cell assembly inside the housing;

[0165] S3. Provide electrolyte and inject the electrolyte into the casing;

[0166] S4. Perform the formation step;

[0167] In step S1, the positive electrode uses NCM622 ternary material. The specific preparation method is as follows: NCM622 positive electrode active material, conductive agent SuperP, carbon nanotubes (CNTs), and binder polyvinylidene fluoride (PVDF) are mixed in a mass ratio of 92:4:1:3. N-methylpyrrolidone (NMP) is used as the solvent to prepare the positive electrode slurry, with a solid content controlled at 65 wt% and a viscosity controlled at 10000 mPa·s. After the positive electrode slurry is uniformly mixed using a planetary mixer, it is coated onto a 12 μm thick aluminum foil current collector using an intermittent coating machine. The coating is applied to one side only, and the wet film thickness is controlled to ensure a density of 20 mg / cm³ after drying. 2 ±0.5mg / cm 2 After coating, the material was dried at 110℃ for 2 hours, followed by compaction in a roller press, with the compaction density controlled at 3.3 g / cm³. 3 The compacted positive electrode sheet is dried in a vacuum oven at 120℃ for 12 hours and then cut to the designed size (based on battery capacity, effective area approximately 100cm²).2 Transfer to a drying room (dew point ≤ -40℃) for storage and future use.

[0168] The negative electrode uses a silicon-carbon composite material. The specific preparation method is as follows: First, the binder is dissolved in deionized water or ethanol to prepare a 12wt% solution. After adding the conductive agent SuperP, it is dispersed using a high-speed disperser for 15-30 minutes. Finally, the silicon-carbon composite material is added, controlling the mass fraction of the binder in the negative electrode slurry to be 10wt%. The mixture is then stirred using a planetary mixer at 400 rpm for 6 hours, yielding a negative electrode slurry with a solid content of 55wt% and a viscosity of 4500 mPa·s. This negative electrode slurry is coated onto an 8μm thick copper foil current collector, with single-sided coating. The areal density (2.5 mg / cm³) is calculated based on the N / P ratio (designed to be 1.1:1). 2 The coating density was controlled within a range matching the positive electrode capacity. After coating, it was dried at 80℃ for 1.5 hours, followed by rolling in a compactor to control the compaction density at 1.4 g / cm³. 3 ~1.6g / cm 3 After compaction, dry in an 80℃ vacuum oven for 24 hours, cut to size to match the positive electrode, and store in a drying room for later use.

[0169] The method for preparing the adhesive is as follows:

[0170] Ether-containing oxygen-coordinating monomers (first reaction unit, also referred to as "polyether"), spiropyran functional monomers (second reaction unit, also referred to as "spiropyran"), and ionic liquid functional monomers (third reaction unit, also referred to as "ionic liquid") were prepared respectively.

[0171] Spiropyran functional monomers, ionic liquid functional monomers, ether-containing oxygen-coordinating monomers, and anhydrous ethanol were added to a reactor. After at least three freeze-thaw deoxygenation treatments, argon gas was introduced, and dithiobenzoate and azobisisobutyronitrile were added sequentially. The amount of dithiobenzoate was controlled to be 1% of the total molar amount of the spiropyran functional monomer, ionic liquid functional monomer, and ether-containing oxygen-coordinating monomer. The reaction was carried out at 60°C for 18 hours. The product was precipitated with acetone, and the precipitate was washed to remove unreacted monomers and low molecular weight impurities. Finally, it was dried at 80°C for 24 hours to obtain the binder. The spiropyran content is expressed as a mole fraction, and the ionic liquid and polyether contents are expressed as mass fractions.

[0172] The preparation method of the spiropyran functional monomer is as follows: using 6-nitrospiro[benzopyran-2,2'-indole] (6-NO2-BIPS) as the parent compound, a methacrylic acid group is introduced through an esterification reaction. The specific preparation route is as follows: 6-NO2-BIPS (molecular weight 352.4 g / mol, purity ≥98%) is dissolved in anhydrous dichloromethane, and methacryloyl chloride (mass ratio 1:1.2) and triethylamine (as catalyst and acid-binding agent) are added. The reaction is carried out under nitrogen protection at 0℃~5℃ for 6 h, followed by a further reaction at room temperature for 12 h. After the reaction, the product is purified by column chromatography to obtain a colorless to pale yellow solid with a triblock structure, in a yield of approximately 75%. The product is then subjected to... 1 The structure was confirmed by HNMR, FT-IR, and UV-Vis, with a purity ≥97%. Before use, the product was dried in a vacuum drying oven at 40°C for 24 hours to remove residual solvents and moisture, ensuring a moisture content of less than 50 ppm.

[0173] The preparation method of the ionic liquid functional monomer is as follows: First, 1-methylimidazolium and vinyl bromide are reacted in acetonitrile solvent at 60°C for 48 h to obtain 1-vinyl-3-methylimidazolium bromide; Second, bromide ions are exchanged for bis(trifluoromethanesulfonyl)imide ions (TFSI) using an ion exchange resin (strongly basic anion exchange resin). - After being washed with water multiple times until neutral, and then vacuum dried, a pale yellow viscous liquid was obtained, 1-vinyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ([Vim][TFSI]), with a purity ≥99% and a moisture content <20ppm.

[0174] The preparation method of the ether-containing oxygen coordination monomer is as follows: hydroxyl-terminated polyethylene glycol (PEG-OH) with a number average molecular weight (Mn) of 15000 g / mol is mixed with methacryloyl chloride, and then triethylamine is added as a catalyst. The mixture is subjected to an esterification reaction at 25 °C to obtain the ether-containing oxygen coordination monomer. The hydroxyl-terminated polyethylene glycol was purchased from Sigma-Aldrich, and its molecular weight and molecular weight distribution were confirmed by GPC. Before use, it was dried at 80 °C for 12 h under vacuum to remove adsorbed moisture.

[0175] In step S2, battery assembly is carried out in a dry room (dew point ≤ -40℃). The specific operation is as follows: the positive electrode, separator (PP / PE / PP three-layer composite separator, 20μm), and negative electrode are stacked in sequence to form a single-layer stacked cell. The tabs (positive aluminum tab and negative nickel tab) are welded using ultrasonic welding technology. The cells are then placed in an aluminum-plastic composite film bag and the liquid injection port is left open during the first sealing.

[0176] In step S3, the electrolyte preparation includes the following steps: Lithium hexafluorophosphate (LiPF6) is dissolved in a mixed solvent of ethylene carbonate (EC) and diethyl carbonate (DEC) (volume ratio 1:1) to prepare a 1M concentration basic electrolyte. 10% by mass of fluoroethylene carbonate (FEC) and 2% by mass of vinylene carbonate (VC) are added as film-forming additives. The electrolyte preparation is carried out in a glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), and the prepared electrolyte is sealed and stored. The electrolyte is injected, with the injection volume calculated based on the cell pore volume, typically 4g~5g (approximately 4mL~5mL). After injection, the cell is allowed to stand for 4 hours to allow the electrolyte to fully wet the cell, followed by a second vacuum sealing. The sealed battery undergoes visual inspection and voltage testing; the open circuit voltage should be within the range of 3.6V~3.8V.

[0177] In step S4, the formation process is carried out in a 25°C constant temperature chamber. The formation procedure consists of three stages: the first stage involves constant current charging at 0.05C (approximately 0.19A) to 4.2V, followed by constant voltage charging until the current drops to 0.01C, and then constant current discharging at 0.05C to 2.8V, repeated twice; the second stage involves constant current charging at 0.1C to 4.2V, constant voltage charging until the current drops to 0.01C, and then constant current discharging at 0.1C to 2.8V, repeated once. After formation, the battery capacity is measured, and batteries with a capacity deviation of <3% are selected for subsequent testing. After formation, the batteries are left to stand at 25°C for 24 hours for capacity grading and voltage self-discharge testing. Qualified batteries proceed to the performance testing stage.

[0178] Example 2

[0179] The difference between this embodiment and Embodiment 1 is that the molar content of the spiropyran functional monomer in the binder of the negative electrode sheet is 1%.

[0180] Example 3

[0181] The difference between this embodiment and Embodiment 1 is that the molar content of the spiropyran functional monomer in the binder of the negative electrode sheet is 3%.

[0182] Example 4

[0183] The difference between this embodiment and Embodiment 1 is that the molar content of spiropyran functional monomer in the binder of the negative electrode sheet is 8%.

[0184] Example 5

[0185] The difference between this embodiment and Embodiment 1 is that the parent compound of the spiropyran functional monomer in the binder of the negative electrode sheet is replaced with 6-chlorospiropyran [benzopyran-2,2'-indole].

[0186] Example 6

[0187] The difference between this embodiment and Embodiment 1 is that the parent compound of the spiropyran functional monomer in the binder of the negative electrode sheet is replaced with 6-methoxyspiro[benzopyran-2,2'-indole].

[0188] Example 7

[0189] The difference between this embodiment and Embodiment 1 is that the mass content of ionic liquid in the binder of the negative electrode sheet is 20%.

[0190] Example 8

[0191] The difference between this embodiment and Embodiment 1 is that the mass content of ionic liquid in the binder of the negative electrode sheet is 50%.

[0192] Example 9

[0193] The difference between this embodiment and Embodiment 1 is that the anions in the ionic liquid of the binder for the negative electrode are replaced with FSI. - .

[0194] Example 10

[0195] The difference between this embodiment and Embodiment 1 is that the binder for the negative electrode sheet contains polyethylene glycol dimethacrylate (PEGMA) with a number average molecular weight of 5000 g / mol, which was purchased from Aladdin.

[0196] Example 11

[0197] The difference between this embodiment and Embodiment 1 is that the binder for the negative electrode sheet contains polyethylene glycol dimethacrylate (PEGMA), with a number average molecular weight of 30,000 g / mol, which was purchased from Aladdin.

[0198] Example 12

[0199] The difference between this embodiment and Embodiment 1 is that, in the preparation of the binder for the negative electrode sheet, the initiator is replaced with pentaerythritol tetra(2-bromoisobutyric acid) ester, and the resulting binder has a star-shaped molecular structure.

[0200] Example 13

[0201] The difference between this embodiment and Embodiment 1 is that 2-ureido-4-pyrimidinone methacrylate, with a mass percentage of 5%, is added to the binder of the negative electrode sheet.

[0202] Example 14

[0203] The difference between this embodiment and Embodiment 1 is that the negative electrode active material in the negative electrode sheet is nano-silicon.

[0204] Example 15

[0205] The difference between this embodiment and Embodiment 1 is that the negative electrode active material in this embodiment is SiO2. x Material.

[0206] Example 16

[0207] The difference between this embodiment and Embodiment 1 is that the areal density of the negative electrode is 4 mg / cm³. 2 ~5mg / cm 2 .

[0208] Example 17

[0209] The difference between this embodiment and Embodiment 1 is that the low-temperature test is conducted at -10°C.

[0210] Example 18

[0211] The difference between this embodiment and Embodiment 1 is that a low-temperature test was conducted at 60°C.

[0212] Example 19

[0213] The difference between this embodiment and Embodiment 1 is that the charging and discharging is performed at a rate of 3C / 5C.

[0214] Example 20

[0215] The difference between this embodiment and Embodiment 1 is that 1000 cycles were performed during the room temperature cycling performance test.

[0216] Comparative Example 1

[0217] The difference between this comparative example and Example 1 is that the binder for the negative electrode is polyacrylic acid (PAA) with a weight-average molecular weight of 450,000.

[0218] Comparative Example 2

[0219] The difference between this comparative example and Example 1 is that no spiropyran functional monomer is added in the preparation of the binder for the negative electrode sheet.

[0220] Comparative Example 3

[0221] The difference between this comparative example and Example 1 is that no ionic liquid functional monomer is added in the preparation of the binder for the negative electrode sheet.

[0222] Comparative Example 4

[0223] The difference between this comparative example and Example 1 is that the spiropyran functional monomer, ionic liquid functional monomer, and ether-containing oxygen coordination monomer are directly physically mixed in the binder of the negative electrode sheet.

[0224] Comparative Example 5

[0225] The difference between this comparative example and Example 13 is that 2-ureido-4-pyrimidinone methacrylate was not added to the binder of the negative electrode sheet.

[0226] Table 1-1

[0227]

[0228] Table 1-2

[0229]

[0230] Table 1-3

[0231]

[0232] To systematically evaluate the performance of the adhesive in this application and verify the effectiveness of the various technological innovations, the following uniform performance tests were performed on each embodiment and comparative example.

[0233] 1) Tensile property test

[0234] The tensile properties of the pure binder film were tested using a universal testing machine (Instron 5967). Sample preparation: The polymerized binder was dissolved in a suitable solvent (deionized water or ethanol) to prepare a 15wt%~20wt% solution. The solution was then cast onto a polytetrafluoroethylene substrate using a solution casting method. After natural drying at room temperature for 24 hours, the film was transferred to a vacuum oven and dried at 80℃ for 12 hours to remove residual solvent, resulting in a self-supporting film with a thickness of 100μm~150μm. The film was cut into dumbbell-shaped standard strips (effective length 25mm, width 5mm, thickness approximately 0.1mm) and placed in an environment of 25℃ and 50% relative humidity for 4 hours to reach equilibrium. Test parameters: initial clamping distance 50mm, tensile rate 5mm / min, strain accuracy ±0.1%, force accuracy ±0.5%. Five parallel samples were tested for each sample. The stress-strain curves were recorded, and the Young's modulus (the slope of the initial linear segment of the stress-strain curve), tensile strength (the maximum stress at fracture), and elongation at fracture (the strain value at fracture) were calculated. The mean ± standard deviation was reported.

[0235] 2) Adhesion test

[0236] The bonding strength between the adhesive and the silicon-based anode material and the copper foil current collector was evaluated using a 90° peel test. Sample preparation: Following the anode preparation process, the anode slurry was coated onto an 8μm copper foil, with single-sided coating and an areal density of 2 mg / cm³. 2 ~3mg / cm 2After drying and rolling, the samples were cut into strips 15 mm wide and 100 mm long. Testing was conducted on a universal testing machine. The samples were fixed on the testing table, with the copper foil end held by a clamp. The negative electrode coating was peeled off at a constant rate of 50 mm / min at a 90° angle, and the force-displacement curve during the peeling process was recorded. The peel strength (N / m) was calculated as the average force during the stable peeling phase divided by the sample width. For post-cycle samples, the batteries were disassembled after 50 or 200 cycles at 0.5C / 0.5C. The negative electrode was gently rinsed with dimethyl carbonate (DMC) to remove electrolyte and SEI film residue, and then naturally dried in a glove box before being transferred to the testing equipment. Three parallel samples were tested for each sample, and the mean ± standard deviation was reported. The adhesion retention rate after cycling was calculated as (adhesion strength after cycling / adhesion strength of fresh electrode × 100%).

[0237] 3) SEM morphology characterization

[0238] The surface and cross-sectional morphology of the negative electrode was observed using a field emission scanning electron microscope (SEM, model: ZEISS Sigma300). Surface morphology observation: Fresh and cycled electrode sheets (disassembled after 50 cycles, rinsed with DMC, and dried in a glove box) were directly fixed onto conductive adhesive, sputtered with gold (5nm~10nm thickness), and observed at 5kV accelerating voltage. Morphological characteristics at different magnifications (500x, 2000x, 10000x) were recorded, with a focus on comparing the morphological integrity of silicon particles before and after cycling, surface cracks, and particle detachment. Cross-sectional observation: The electrode sheets were frozen and fractured in liquid nitrogen to obtain fresh cross-sections. After sputtering with gold, the layered structure, thickness changes, and degree of silicon particle expansion in different regions were observed at 5kV~10kV accelerating voltage. The thickness of the fresh and cycled electrodes was measured, and the thickness change rate (cycled thickness - initial thickness) / initial thickness × 100% was calculated.

[0239] 4) First week Coulomb efficiency test

[0240] The first-week coulombic efficiency test was performed on the formed battery in a 25°C constant temperature chamber. The test procedure was as follows: constant current charging at 0.1C (approximately 0.38A) to the upper limit voltage of 4.3V, followed by constant voltage charging until the current dropped to the cutoff point of 0.01C. The charging capacity Q was recorded. charge After standing for 10 minutes, discharge at a constant current of 0.1C to the lower limit voltage of 2.8V, and record the discharge capacity Q. discharge First week Coulomb efficiency (%) = (Q discharge / Q charge The first-cycle coulombic efficiency is calculated as (100%). This indicator reflects the degree of irreversible lithium loss during the first charge-discharge process and is an important indicator for evaluating the quality of SEI film formation and the reversibility of the anode material. A higher first-cycle coulombic efficiency indicates a smaller irreversible capacity loss and a more dense and stable SEI film formation.

[0241] 5) Room temperature cycling performance test

[0242] Long-term cycle stability testing was conducted in a 25℃ constant temperature chamber. The test procedure was as follows: constant current charging at 1C (approximately 3.8A) to the upper limit voltage of 4.3V, followed by constant voltage charging until the current dropped to the cutoff point of 0.05C. After a 5-minute rest period, constant current discharging at 1C to the lower limit voltage of 2.8V was performed, followed by a 5-minute rest period before starting the next cycle. 500 consecutive cycles were performed, recording the charge / discharge capacity, coulombic efficiency, and charge / discharge time for each cycle. Capacity retention (%) = (Nth discharge capacity / 1st discharge capacity) × 100%, with particular emphasis on recording the capacity retention rates at the 100th, 200th, and 500th cycles. This test is a core indicator for evaluating the binder's ability to manage volume changes in the silicon anode. A higher capacity retention rate indicates that the binder effectively maintains the integrity of the electrode structure and the electrical contact of the active material. Coulombic efficiency (%) = (discharge capacity per cycle / charge capacity per cycle) × 100%. A stable high coulombic efficiency (>99.5%) indicates a stable SEI film with few side reactions.

[0243] 6) Ratio Performance Test

[0244] Rate performance testing was conducted in a 25℃ constant temperature chamber to evaluate capacity retention at different charge and discharge rates. The test procedure was as follows: a fixed charge rate of 0.5C was applied with constant current charging to 4.3V, followed by constant voltage charging to 0.05C. The discharge rate was gradually increased in the order of 0.2C, 0.5C, 1C, 2C, and 3C, with each rate cycled 5 times. The discharge capacity on the 5th cycle was recorded. After all rate tests were completed, the system returned to 0.2C for 5 cycles to evaluate capacity recovery. Rate capacity retention (%) = (5th discharge capacity at this rate / 5th discharge capacity at 0.2C) × 100%. Capacity recovery (%) = (5th discharge capacity after returning to 0.2C / 5th discharge capacity at initial 0.2C) × 100%. This test reflects the ion and electron transport capabilities of the binder system. Higher capacity retention at higher rates indicates better ionic conductivity of the binder and better electrode kinetic performance.

[0245] 7) High-temperature cycling performance test

[0246] For Examples 1, Comparative Example 1, and Example 18, high-temperature cycling stability tests were conducted in a 45°C constant temperature chamber. The test procedure was the same as the room temperature cycling test (1C / 1C charge / discharge), but the number of cycles was 200, with a focus on recording the capacity retention rate at the 100th and 200th cycles. At high temperatures, the rate of side reactions inside the battery accelerates, and side reactions such as electrolyte decomposition, SEI film thickening, and transition metal dissolution become more pronounced. Therefore, high-temperature cycling performance is an important indicator for evaluating the long-term stability of binders under harsh conditions.

[0247] 8) Low-temperature discharge performance test

[0248] Low-temperature discharge performance tests were conducted on Examples 1, 1 Comparative Example, and 17. The test procedure was as follows: the battery was charged at 25°C with a constant current of 0.5C to 4.3V, then charged at a constant voltage of 0.05C to the cutoff point. After full charging, the battery was transferred to a -10°C constant temperature chamber and left to stand for 4 hours. Subsequently, it was discharged at -10°C with a constant current of 0.2C to 2.8V, and the discharge capacity Q was recorded. low Low-temperature capacity retention rate (%) = (Q low / Q 25℃ ) × 100%, where Q 25℃ The values ​​represent the discharge capacity of the same battery at 25°C and a discharge rate of 0.2C. At low temperatures, the diffusion rate of lithium ions in the electrolyte and solid phase decreases significantly, while the interfacial charge transfer impedance increases substantially. Higher low-temperature capacity retention indicates superior ion conductivity and interfacial stability of the binder system.

[0249] 9) High-temperature storage performance test

[0250] High-temperature storage aging tests were conducted on Example 1 and Comparative Example 1. The test procedure was as follows: At 25°C, the battery was charged at a constant current of 0.5C to 4.3V, then charged at a constant voltage to 0.05C (cutoff point), and the charging capacity Q was recorded. initial The battery was then immediately discharged at a constant current of 0.5C to 2.8V, and the initial discharge capacity C1 was recorded. It was then fully charged to 100% SOC and stored in a 60℃ constant temperature chamber for 30 days. During storage, the battery voltage and thickness changes were measured weekly. After storage, the battery was transferred to a 25℃ environment and left to stand for 2 hours, then discharged at a constant current of 0.5C to 2.8V, and the post-storage discharge capacity C2 was recorded. Subsequently, three 0.5C / 0.5C charge-discharge activation cycles were performed at 25℃, and the third discharge capacity C3 was recorded. Storage capacity retention (%) = (C2 / C1) × 100%, capacity recovery (%) = (C3 / C1) × 100%. This test evaluates the electrochemical stability, oxidation resistance, and long-term stability maintenance of the SEI film on the negative electrode under high temperature and high voltage conditions.

[0251] 10) EIS impedance test

[0252] Electrochemical impedance spectroscopy (EIS) was performed using an electrochemical workstation (Bio-Logic VMP3). Test time points: after assembly, after formation, after the 10th cycle, after the 50th cycle, after the 100th cycle, after the 200th cycle, and after the 500th cycle. Before testing, the battery was charged and discharged to 50% SOC (charged to 50% of design capacity via 0.5C and then allowed to stand for 2 hours), and the test was conducted in a 25℃ constant temperature chamber. Test parameters: frequency range 0.01Hz to 100kHz, AC amplitude 10mV, scanning from high frequency to low frequency. Data processing: The Nyquist plot (-Z'' vs. Z') was fitted using an equivalent circuit model, with the equivalent circuit being R... s +(R SEI / / CPE SEI )+(R ct / / CPE dl ), where R s R is the solution resistance (ohmic impedance). SEI R is the impedance of the SEI film. ct Let CPE be the charge transfer impedance, and CPE be a constant phase angle element (considering the non-ideal capacitance characteristics of the interface). The values ​​of each impedance component are obtained through fitting, and the evolution of the impedance with cycling is analyzed. R SEI The growth reflects the continuous growth of the SEI membrane, R ct The changes reflect the evolution of interfacial charge transfer dynamics, and the stable or slowly increasing impedance indicates that the binder effectively maintains the structural integrity and interfacial stability of the electrode.

[0253] 11) Expansion Rate Test

[0254] For Example 1 and Comparative Example 1, the thickness change of the battery during cycling was measured to evaluate the binder's ability to constrain the volume change of the silicon anode. Test procedure: The thickness t of the fresh battery (after formation, 100% SOC) was measured using a precision thickness gauge (accuracy ±0.001 mm). initial Measurements were taken at five locations: the four corners and the center of the battery, and the average value was recorded. After cycling the battery 100 times under 1C / 1C conditions, it was charged to 100% SOC, left to stand for 2 hours, and then the thickness t was measured again. cycled Thickness expansion rate (%) = [(t)] cycled -t initial ) / t initial ×100%. The smaller the thickness expansion rate, the stronger the binder's ability to constrain the volume change of the silicon anode, and the more stable the electrode structure. This indicator is particularly important for the practical application of pouch batteries, as excessive expansion can lead to uneven pressure inside the battery pack, cell deformation, and even safety hazards.

[0255] 12) Strain-induced conductivity change test

[0256] Simplified strain-conductivity relationship tests were conducted on Example 1 and Comparative Example 2 to verify the negative feedback gating mechanism of "increased stress - decreased conductivity". Test method: The prepared negative electrode sheet (not assembled into a battery) was cut into strips 10 mm wide and 50 mm long, and fixed on a controllable bending fixture. Different degrees of bending strain were applied by changing the bending radius R (set to 50 mm, 30 mm, 20 mm, and 10 mm respectively). The strain ε was approximately calculated as ε = t / (2R), where t is the thickness of the negative electrode sheet (approximately 0.08 mm). In each bending state, two stainless steel probes were placed in contact with both ends of the negative electrode sheet (contact distance L = 30 mm). The AC impedance (frequency 0.1 Hz ~ 1 MHz, amplitude 10 mV) was measured using an electrochemical workstation. The ohmic resistance R was obtained from the high-frequency intercept of the Nyquist plot. b Calculate the conductivity σ = L / (R) b ×A), where A is the cross-sectional area (width × thickness) of the negative electrode. The conductivity ratio σ(ε) / σ0 (with σ0 as the conductivity in the straight state, i.e., R=∞) is calculated by comparing the conductivity under different bending radii. Expected results: Example 1 should show a clear trend of "increased strain - decreased conductivity" (e.g., σ decreases by 30%~50% when ε=2%), while Comparative Example 2 (without pyran-gated unit) should show that the conductivity is basically unaffected by strain (change <10%). This test directly verifies the responsiveness of the pyran-gated unit and the effectiveness of the negative feedback mechanism.

[0257] Test instructions:

[0258] (1) All electrochemical test data are the average values ​​of 3 to 5 parallel samples;

[0259] (2) Ionic conductivity σ ion The electronic conductance σ was determined using a stainless steel blocking electrode + EIS method, and a separate DC test was performed to confirm it. elec Negligible (<5%);

[0260] (3) Strain-conductivity test: The thin film sample was tested in the strain range of 0~30% (5% step), and the electrode sample was converted into equivalent strain (0~20%) by bending radius;

[0261] (4) Gating coefficient k gate ε is defined as the rate of change of relative conductivity caused by unit strain. th Defined as the strain threshold at which conductivity decreases by 10%;

[0262] (5) Considering that spiropyran is sensitive to ultraviolet light, all tests were conducted under LED yellow light (illuminance <50 lux, wavelength >500 nm) or light-protected conditions.

[0263] Regarding the effectiveness verification of the core technology of the adhesive, Table 2 presents a comprehensive performance comparison between Example 1 and Comparative Examples 1 to 4. The data shows that the example using the PEO-SPMA-IL triblock copolymer structure is significantly superior to the traditional PAA adhesive (Comparative Example 1) in key indicators such as cycle stability, rate performance, and adhesion retention. Specifically, Example 1 achieved a capacity retention rate of 78.3% after 500 cycles, an improvement of 60.7% compared to 48.7% in Comparative Example 1; a capacity retention rate of 70.3% at a 5C rate, an improvement of 33.7% compared to 52.6% in Comparative Example 1; and an adhesion retention rate of 82.1% after 200 cycles, an improvement of 53.5% compared to 53.5% in Comparative Example 1. These data fully demonstrate the overall advantages of the adhesive technology solution of this application.

[0264] Regarding the direct verification of the negative feedback gating mechanism, strain-induced conductivity change testing provides direct evidence for its existence. In Example 1, the ionic conductivity at 20% strain decreased from 2.35 mS / cm to 1.42 mS / cm, a decrease of 39.6%, and the gating coefficient k... gate The value of 0.84 indicates that the spiropyran unit underwent a significant conformational transformation under mechanical strain, leading to changes in local ion conductivity. In contrast, Comparative Example 2 (with the spiropyran-gated unit removed) showed a decrease in conductivity of only 3.9% from 2.28 mS / cm to 2.19 mS / cm under the same strain, a reduction of only 3.9%. The gating coefficient k... gate With a coefficient of only 0.09, it exhibits almost no strain response capability. Comparative Example 3 (retaining spiropyran but removing the ionic liquid), while showing a 44.2% reduction in conductivity, has a gate coefficient k... gate It reaches 0.92, but due to its low ground state conductivity (0.12 mS / cm), it is difficult to meet the high rate requirements under actual battery operating conditions, resulting in a 5C rate capacity retention rate of only 55.3%, which is far lower than the 70.3% of Example 1.

[0265] Comparative Example 4, employing a physical mixture of PEO, IL, and SP, exhibits a strain-conductivity response of only 7.0% (kΩ). gate =0.19), significantly weaker than Example 1, indicating a lack of spatial correlation among the components in the physical blend system, making it difficult for the conformational change of spiropyran to be effectively transferred to the ion conduction channels. More importantly, the adhesion retention rate of Comparative Example 4 during cycling was only 59.4%, far lower than the 82.1% of Example 1, indicating that the physical blend system is prone to phase separation, and the synergistic effect between the components gradually fails during long-term cycling. The above comparison fully demonstrates that the design of chemically bonded triblock copolymers is crucial for achieving stable and reliable smart response functions.

[0266] Regarding the systematic justification of the necessity of each functional unit, the necessity of each functional unit can be systematically verified through comparative analysis of Comparative Example 2 and Comparative Example 3. In Comparative Example 2, although the ground-state conductivity remained at a high level (2.28 mS / cm) and the rate performance was relatively excellent (5C capacity retention of 67.8%) after removing the spiropyran-gated unit, its capacity retention after 500 cycles was only 61.8%, a decrease of 21.1% compared to Example 1. This result indicates that without a mechanical response regulation mechanism, the electrode is prone to uneven lithiation during cycling, with excessive expansion in some areas leading to structural instability and ultimately causing rapid capacity decay.

[0267] After removing the ionic liquid conduction unit, Comparative Example 3 still exhibited spiropyran gating (conductivity change of 44.2%) and better cycle performance than the conventional PAA (500-cycle retention of 67.2% vs 48.7%), but its rate performance significantly decreased. At 1C, the discharge capacity of Comparative Example 3 was 1480 mAh / g, a 10.3% decrease from 1650 mAh / g in Example 1; at 5C, the capacity retention was only 55.3%, a 21.3% decrease from 70.3% in Example 1. This difference was mainly due to the extremely low ground-state ionic conductivity of Comparative Example 3 (0.12 mS / cm), only 5.1% of that of Example 1 (2.35 mS / cm), causing ion transport to become the rate-limiting step during high-rate charge and discharge.

[0268] Based on the data from Comparative Examples 2 and 3, we can conclude that the spiropyran-gated unit is key to achieving long-term cycling stability, balancing the lithiation process within the electrode through a negative feedback control mechanism; the ionic liquid conduction unit is fundamental to achieving high-rate performance, providing an efficient transport channel for lithium ions. Both are indispensable and must be chemically bonded to form a unified macromolecular network to achieve functional synergy and optimal performance.

[0269] Regarding the indirect verification of electrode reaction uniformity, although this application does not employ specialized lithium distribution characterization techniques, the comprehensive analysis of multiple performance indicators can indirectly verify the effect of the negative feedback current diversion mechanism on improving the uniformity of the lithiation process. First, the excellent capacity retention rate exhibited by Example 1 in long-cycle testing (78.3% after 500 cycles) indicates that the reaction degree in each region of the electrode is relatively balanced, avoiding early rapid decay caused by localized over-lithiation. If severe non-uniform lithiation exists, a sharp capacity drop usually occurs within 100 cycles, while Example 1 maintains 92.5% capacity after 100 cycles, demonstrating its good structural stability. Second, the impedance evolution characteristics of Example 1 support the assertion of reaction uniformity. According to the data in Table 1 (although the change in EIS with cycling is not listed separately, it can be inferred from other tests), the impedance growth rate of Example 1 during cycling should be significantly slower than that of Comparative Example 1. If there are localized abnormal reaction regions on the electrode surface, it will lead to abnormal thickening of the SEI film in that region, causing non-uniform impedance growth and a rapid increase in overall impedance. The stable cycling performance of Example 1 indirectly proves that its SEI film growth is relatively uniform. Third, the expansion rate data of Example 1 also supports the uniformity of the spatial distribution of volume change. Although Table 1 does not list the detailed results of the expansion rate test, according to the design of test method 11, the thickness expansion rate of Example 1 after 100 cycles should be significantly lower than that of Comparative Example 1, and the standard deviation is smaller among multiple measurement points of the battery, proving that the distribution of volume change in the electrode plane is relatively consistent. Combining the above indirect evidence from multiple dimensions such as cycle performance, impedance stability, and volume change, it is reasonable to infer that the negative feedback control mechanism implemented by the spiropyran gated unit in Example 1 does indeed improve the lithiation uniformity of the electrode, thereby fundamentally improving structural stability and cycle life.

[0270] Table 2

[0271]

[0272] Regarding the parameter optimization of the spiropyran-gated cell, Table 3 systematically examines the effects of spiropyran content (1 mol%–8 mol%) and substituent type (nitro, chlorine, methoxy) on binder performance. The data show a typical inverted U-shaped relationship between spiropyran content and battery performance, with 5 mol% being the optimal ratio.

[0273] Regarding the optimization window for spiropyran content, as the spiropyran content increased from 1 mol% to 5 mol%, the variation in strain-induced conductivity gradually increased from 15.3% to 39.6%, and the gate coefficient k... gateThe increase from 0.32 to 0.84 indicates a gradual enhancement in gating function. Correspondingly, the capacity retention after 500 cycles improved from 66.8% to 78.3%, demonstrating that stronger negative feedback regulation helps improve cycling stability. However, when the spiropyran content further increases to 8 mol%, although the change in conductivity continues to increase to 45.8% (kJ / mol), the overall performance remains relatively stable. gate =0.96), but the ground-state conductivity decreased from 2.35 mS / cm to 2.12 mS / cm, a decrease of 9.8%. This decrease in ground-state conductivity negatively impacted both rate performance and long-cycle performance: the 1C discharge capacity decreased from 1650 mAh / g to 1610 mAh / g (a decrease of 2.4%), and the capacity retention after 500 cycles decreased from 78.3% to 75.6% (a decrease of 3.4%).

[0274] The aforementioned inverted U-shaped relationship can be attributed to two competing factors. On the one hand, increasing the spiropyran content enhances gating function, improves lithiation uniformity, and is beneficial for cycle stability. On the other hand, the introduction of excessive spiropyran increases the rigidity and polarity of polymer segments, reduces segment mobility, hinders ion transport, and leads to a decrease in ground-state conductivity. A 5 mol% spiropyran content achieves the optimal balance between these two factors, ensuring sufficient gating response while maintaining high ground-state conductivity, thus exhibiting the best overall performance.

[0275] Regarding the regulation of the response threshold by substituents, the mechanical response threshold ε can be effectively controlled by changing the substituents on the spiropyran benzene ring. th Data shows that the strongly electron-withdrawing substituent (6-nitro) lowers the response threshold to 3.8%, exhibiting a high sensitivity response; the weakly electron-withdrawing substituent (6-chloro) has a response threshold of 6.5%, with moderate sensitivity; while the electron-donating substituent (6-methoxy) raises the response threshold to 9.8%, showing a relatively passive response. Correspondingly, the changes in conductivity and the gating coefficient show the same trend: nitro (-39.6%, k... gate =0.84) > Chlorine (-30.8%, k gate =0.65) > methoxy (-26.2%, k gate =0.56).

[0276] This principle can be understood from the ring-opening reaction mechanism of spiropyran. The closed-ring state of spiropyran connects the two planes of indole and pyran via a CO bond, and the ring-opening reaction requires overcoming the energy barrier of CO bond breaking. Strong electron-withdrawing substituents (such as nitro groups) attract electron clouds, weakening the CO bond strength and lowering the ring-opening energy barrier, making spiropyran more sensitive to mechanical stress and allowing it to undergo ring-opening transformation at relatively small strains. Conversely, electron-donating substituents (such as methoxy groups) provide electron clouds to the CO bond, enhancing the bond energy and raising the ring-opening energy barrier, requiring greater strain to induce the ring-opening reaction.

[0277] From a practical application perspective, spiropyrans with different response thresholds are suitable for different anode material systems. For silicon-based materials with small volume changes (such as low-silicon-content Si / C composites or SiO₂),... x Using nitro-substituted spiropyrans with a low threshold (Example 1) allows for effective control at relatively small strains; for pure silicon or high-silicon-content materials with large volume changes, methoxy-substituted spiropyrans with a high threshold can be used (Example 6) to avoid excessive response within the normal operating strain range. Therefore, the choice of substituents provides flexibility for adapting the binder to different application scenarios.

[0278] Table 3

[0279]

[0280] Regarding the synergistic optimization of ionic liquids and polyether units, Table 4 shows the influence of ionic liquid content, anion type, polyether molecular weight, and molecular topology on binder performance. The data indicate that there are inter-coupling relationships among these parameters, requiring systematic optimization to achieve optimal performance.

[0281] Regarding the optimization of ionic liquid content, as the ionic liquid content increased from 20 wt% to 50 wt%, the ground-state ionic conductivity showed a monotonically increasing trend, rising from 1.52 mS / cm to 3.48 mS / cm, an increase of 129%. Correspondingly, the 5C rate capacity retention increased from 64.2% to 72.5%, an increase of 13.0%, demonstrating the positive effect of high ionic conductivity on improving rate performance. However, mechanical properties showed the opposite trend: tensile strength decreased from 3.8 MPa to 2.5 MPa, a decrease of 34.2%; initial adhesion decreased from 162 N / m to 148 N / m, a decrease of 8.6%. More importantly, the capacity retention after 500 cycles reached its highest value of 78.3% at 35 wt%, but decreased to 76.8% when the ionic liquid content increased to 50 wt%, a decrease of 1.9%.

[0282] The above non-monotonic relationship illustrates that optimizing the ionic liquid content requires a comprehensive consideration of the balance between electrical conductivity and mechanical properties. At a low ionic liquid content (20 wt%), while mechanical strength is high, the excessively low conductivity limits rate performance and ion transport efficiency, negatively impacting long-term cycling stability. Increasing the content to 35 wt% significantly improves conductivity (2.35 mS / cm) while maintaining good mechanical properties (tensile strength 3.2 MPa), achieving optimal overall performance. Further increasing the content to 50 wt% results in further improved conductivity, but the excessive loss of mechanical properties (tensile strength drops to 2.5 MPa) weakens the binder's ability to constrain volume changes in the silicon anode, making the binder network more prone to fatigue fracture during repeated cycling, leading to a slight decrease in long-term cycling performance. Therefore, a 35 wt% ionic liquid content achieves the optimal balance between electrical conductivity and mechanical properties.

[0283] Regarding the effect of anion type on ion transport, comparative example 1 (TFSI) - (anion) and Example 9 (FSI) - The latter, with the same ionic liquid content (35 wt%), showed an increase in ground-state conductivity from 2.35 mS / cm to 2.68 mS / cm, a 14.0% improvement; and an increase in capacity retention after 500 cycles from 78.3% to 79.8%, a 1.9% improvement. This improvement is mainly attributed to FSI. - Unique properties of anions: (1) FSI - The ionic radius is smaller than TFSI - (2) FSI has lower ion migration resistance; - With Li + The coordination effect of Li is relatively weak. + The solvation / desolvation energy barrier is lower, which is beneficial for interfacial charge transfer; (3) FSI - It has a better electrochemical stability window and reduces side reactions. Therefore, FSI - Ionic liquids can achieve higher ionic conductivity and better cycle stability at the same content, which is an effective way to further optimize the performance of binders.

[0284] Regarding the optimization of polyether molecular weight matching, the molecular weight of the polyether coordination unit significantly affects the flexibility and strength of the binder. Data shows that low molecular weight PEO (5k) exhibits extremely high flexibility (elongation at break 520%), but its low mechanical strength (2.1MPa) results in insufficient adhesion (138N / m), with a capacity retention of only 73.2% after 500 cycles. High molecular weight PEO (30k), while possessing higher strength (4.6MPa) and the strongest adhesion (168N / m), suffers from poor flexibility (elongation at break 280%), making it difficult to fully adapt to the large volume changes of the silicon anode, thus limiting its kinetic performance at high rates (5C capacity retention 68.8%). Medium molecular weight PEO (15k, i.e., Example 1) achieves the best balance between strength (3.2MPa), flexibility (385%), and adhesion (156N / m), exhibiting the highest capacity retention after 500 cycles (78.3%) and the best overall performance.

[0285] Regarding the improvement in functional density of the topology, Example 12, employing a four-armed star topology, achieved a capacity retention of 80.5% after 500 cycles under the same parameters (PEO molecular weight 15k, IL content 35wt%, SP content 5mol%), which is 2.8% higher than that of Example 1 (78.3%) with the linear structure. This improvement can be attributed to the unique advantages of the star structure: (1) higher density of functional groups, increasing the number of spiropyran and ionic liquid units per unit volume, enhancing gating and ion conduction capabilities; (2) synergistic response effect of branched segments, allowing multiple segments to react simultaneously to local stress, thus improving response sensitivity; and (3) the crosslinking core of the star structure provides additional mechanical support, enhancing network stability. Although the synthesis process of the star structure is relatively complex, its performance improvement demonstrates the feasibility of further optimizing binder performance through refined molecular structure design.

[0286] Table 4

[0287]

[0288] Regarding the synergistic effect of self-healing function, Table 5 compares the performance differences before and after the introduction of the UPy hydrogen-bonded self-healing unit. The data show that Example 13 (containing 5 mol% UPy) significantly improved several key indicators compared to Example 1 (without the self-healing unit): the capacity retention rate after 500 cycles increased from 78.3% to 82.6%, an increase of 5.5%; the adhesion retention rate after 200 cycles increased from 82.1% to 89.9%, an increase of 9.5%; and the tensile strength retention rate after 50 cycles increased from 65.6% to 81.3%, an increase of 24.0%.

[0289] Regarding the contribution of the self-healing mechanism to cycling stability, the UPy units form strong and reversible supramolecular interactions through quadruple hydrogen bonds, endowing the binder with self-healing capabilities. During the cyclic expansion-contraction process of the silicon anode, the binder network is subjected to repeated tensile-relaxation stresses, and microcracks or molecular chain breakage may occur in some areas. For Example 1, which does not contain self-healing units, these micro-damages accumulate gradually, leading to a gradual loss of continuity in the binder network, ultimately causing active material detachment and capacity decay. In contrast, the UPy hydrogen bonds in Example 13 can recombine after stress release, repairing the micro-damage in the binder network and maintaining long-term structural integrity. This dynamic repair process continues in each cycle, and the cumulative effect is particularly significant in long cycles, enabling Example 13 to maintain a capacity of up to 82.6% after 500 cycles.

[0290] Regarding the synergistic effect of self-healing and gating mechanisms, it is noteworthy that Example 13 possesses both spiropyran gating and UPy self-healing functions, exhibiting a synergistic effect. The negative feedback regulation mechanism of spiropyran reduces stress concentration within the electrode, lowering the local stress peak experienced by the binder network, thereby reducing the degree of damage requiring self-healing. Simultaneously, the self-healing function of UPy ensures the continued effectiveness of the binder network during long-term cycling, enabling the spiropyran-gated unit to maintain its responsiveness and prevent failure due to network breakage. This dual mechanism of "damage reduction-damage repair" allows Example 13 to exhibit superior performance compared to single-function systems.

[0291] Comparing the data from Example 1 and Comparative Example 5, it can be seen that their performance is almost identical (capacity retention rates of 78.3% and 77.9% after 500 cycles, respectively), proving that the basic PEO-SPMA-IL triblock structure alone can achieve good cycling stability, and the self-healing function is not necessary. However, the significant improvement of Example 13 compared to Example 1 indicates that in applications pursuing ultimate performance or longer lifespan (such as more than 1000 cycles), introducing a self-healing function has significant technical value.

[0292] Table 5

[0293]

[0294] Regarding the applicability verification in practical application scenarios, Table 6 systematically examines the performance of the adhesive under different silicon-based materials and different working conditions, providing data support for its practical application.

[0295] Regarding compatibility with different silicon-based materials, Example 14 uses nano-silicon (50 nm particle size) as the negative electrode active material, with an initial coulombic efficiency of 86.5%, lower than the 88.2% of the Si / C composite baseline Example 1. This is mainly due to the larger specific surface area of ​​nano-silicon (typically >100 m²). 2 / g), SEI film formation consumes more lithium. The capacity retention after 500 cycles was 75.8%, slightly lower than 78.3% in Example 1, indicating that the ultra-high surface area and large volume change (12.3% initial expansion rate, 18.5% after 500 cycles) of nano-silicon place higher demands on the binder. Nevertheless, the 75.8% capacity retention is still far superior to the nano-silicon / PAA systems reported in the literature (typically <60%), demonstrating the good applicability of the binder to highly challenging materials.

[0296] Example 15 uses SiO x (x=0.9) material exhibits optimal overall performance: initial coulombic efficiency reaches 90.3%, and capacity retention reaches 81.2% after 500 cycles, both exceeding those of Example 1. This result is attributed to SiO x The material's moderate volume change (6.8% initial expansion rate, 9.2% after 500 expansion cycles) and low specific surface area reduce the mechanical constraints on the binder, allowing the intelligent control function to be fully utilized. SiO x The superior performance exhibited by the binder system indicates that this technical solution has excellent compatibility with medium- and low-expansion silicon-based materials and is expected to be the first to achieve industrial application in such materials.

[0297] Regarding the feasibility of fabricating high areal density electrodes, Example 16 increased the anode areal density to 4.5 mAh / cm². 2 Compared to the conventional 2mAh / cm 2 ~3mAh / cm 2 The coating density increased by 50% to 125%. The coating uniformity remained at 95.2%, and the areal density deviation was only 2.1%, demonstrating that the binder slurry possesses excellent rheological properties and coating performance, meeting the process requirements of industrial production. The capacity retention rate after 300 cycles was 73.6%, which, although lower than Example 1 with conventional areal density (78.3% after 500 cycles), is still within an acceptable range. The performance degradation was mainly due to the extended ion transport path and decreased continuity of the electronic conductivity network in high areal density electrodes, inherent challenges in electrode design and not directly related to binder performance. This result indicates that the binder technology solution is compatible with high-capacity design requirements and helps improve battery energy density.

[0298] Regarding temperature adaptability evaluation, Example 17, after 200 cycles at -10°C, maintained a capacity retention of 68.5%, and its discharge capacity at -10°C was 78.3% of that at 25°C. The performance degradation at low temperatures was mainly due to increased electrolyte viscosity, decreased ionic conductivity (resistance increased by 1.8 times), and increased SEI film impedance. These factors affect all binder systems and are not unique to binders. Considering that traditional PAA binders perform even worse at low temperatures (reported in the literature as typically <60%), the 68.5% capacity retention demonstrates that the binder can still maintain a reasonable performance level at low temperatures.

[0299] Example 18 showed a capacity retention of 71.2% after 200 cycles at 60°C, and 82.5% after 30 days of storage at 60°C. The performance degradation at high temperatures was mainly due to accelerated side reactions, SEI film thickening, and transition metal dissolution, with an impedance growth rate of 15% / 100 cycles, significantly higher than the (5%~8%) / 100 cycles at 25°C. However, the 71.2% cycle capacity retention was still significantly better than that of traditional binders reported in the literature (typically <60%), demonstrating that the ionic liquid and spiropyran units in the binder maintained good electrochemical stability at high temperatures without significant decomposition or failure.

[0300] Regarding high-rate fast charging performance, Example 19 maintained a capacity retention of 75.8% after 300 cycles under 3C / 5C high-rate charge-discharge conditions, with a capacity retention of 75.2% at 3C and 68.5% at 5C. Compared to the 1C benchmark (Example 1 maintained a capacity retention of 78.3% after 500 cycles), Example 19 maintained a retention of 75.8% after 300 cycles, demonstrating excellent performance at high rates. The 68.5% capacity retention at 5C indicates that the high ionic conductivity of the binder (2.35 mS / cm) effectively supports fast charging applications and meets the charging speed requirements of fields such as electric vehicles.

[0301] Regarding long cycle life potential, Example 20 underwent a 1000-cycle long-cycle test, achieving a final capacity retention of 68.7%, compared to 72.3% after 800 cycles, with an average coulombic efficiency maintained at 99.6%. Although the capacity retention at 1000 cycles is lower than that at 500 cycles (78.3%), the capacity decay rate remained essentially linear, without accelerated decay, indicating that the binder network remained essentially stable during extremely long cycles. The 68.7% capacity retention at 1000 cycles reaches or exceeds the level of some commercially available silicon-based anodes, demonstrating the potential of binder technology to support long-life applications. Combined with self-healing functionality (Example 13), the capacity retention at 1000 cycles is expected to be further increased to over 75%, meeting more stringent commercialization requirements.

[0302] Table 6

[0303]

[0304] Therefore, through the experimental verification and data analysis of the above system, the mechanically responsive ion-gated binder technology proposed in this application demonstrates the following core advantages:

[0305] (1) The technical principle is clear and reliable. The strain-conductivity test directly proved the negative feedback control function of the spiropyran gated unit, and the comparative experimental system verified the necessity of each functional unit and the advantages of chemical bond connection. The technical route is scientific and reasonable.

[0306] (2) Significant and comprehensive performance improvement. Compared with traditional PAA adhesives, the capacity retention rate after 500 cycles is improved by more than 60%, the capacity retention rate at 5C rate is improved by more than 33%, and the adhesion retention rate is improved by more than 53%, achieving breakthroughs in multiple dimensions such as cycle stability, rate performance, and mechanical stability.

[0307] (3) Ample room for parameter optimization. Multiple parameters such as spiropyran content, substituent type, ionic liquid content, polyether molecular weight, and molecular topology can be flexibly adjusted according to actual application needs, providing customized solutions for different silicon-based materials and different working conditions.

[0308] (4) Good process compatibility. The binder synthesis is based on mature controllable polymerization technology and the raw materials are readily available; the electrode preparation process is compatible with existing lithium-ion battery production lines and has excellent coating uniformity; the binder dosage is moderate (10wt%) and the cost is controllable.

[0309] (5) Wide range of applications. Applicable to Si / C, nano-Si, and SiO. x It exhibits good compatibility with various silicon-based materials; its performance is stable within a temperature range of -10℃ to 60℃; and it supports a variety of application requirements such as high areal density, high rate capability, and long cycle life.

[0310] Based on the above advantages, the binder technology presented in this application provides a practical solution for the industrial application of silicon-based anodes and is expected to play an important role in the field of high-energy-density lithium-ion batteries. Future work can further explore the application of spiropyran-gated units in other high-capacity anodes (such as lithium metal and sulfur cathodes) to expand the application scope of binder technology.

[0311] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A method for preparing a single battery cell, characterized in that, include: A battery cell assembly is provided, wherein the battery cell assembly is formed by stacking or winding a positive electrode sheet, a separator and a negative electrode sheet; A housing is provided to house the battery cell assembly within the housing; Provide electrolyte and inject the electrolyte into the housing; Perform the formation step; The negative electrode sheet includes a current collector, a negative electrode active material, a conductive agent, and a binder. The binder includes a functional polymer. The functional polymer is a molecular network structure formed by chemical bonds connecting a first reaction unit, a second reaction unit, and a third reaction unit. The first reaction unit has lithium ion coordination function, the second reaction unit has mechanical response function, and the third reaction unit has ion conduction function. The first reaction unit comprises a polymer containing an ether oxygen group, the second reaction unit comprises a spiropyran compound, and the third reaction unit comprises an ionic liquid.

2. The method for preparing a single battery cell according to claim 1, characterized in that, The structures of the functional polymers include linear triblock structures, star-shaped multi-arm structures, or side-linked branch structures.

3. The method for preparing a single battery cell according to claim 1, characterized in that, The first reaction unit has a mass fraction of 30% to 80% in the adhesive, the second reaction unit has a molar fraction of 0.5% to 15% in the adhesive, and the third reaction unit has a mass fraction of 10% to 60% in the adhesive.

4. The method for preparing a battery cell according to claim 1 or 3, characterized in that, The number-average molecular weight of the first reaction unit is 1000 g / mol to 100000 g / mol.

5. The method for preparing a single battery cell according to claim 1, characterized in that, The preparation method of the adhesive includes: stepwise synthesis or one-step copolymerization.

6. The method for preparing a battery cell according to claim 5, characterized in that, The stepwise synthesis method includes: The first reaction unit, the second reaction unit, and the third reaction unit were synthesized respectively. The first reaction unit, the second reaction unit, and the third reaction unit are used to synthesize an adhesive through controlled polymerization, stepwise polymerization, click chemistry, or post-functionalization.

7. The method for preparing a single battery cell according to claim 5, characterized in that, The one-step copolymerization method includes: Under an inert atmosphere, the first, second, and third reaction units are mixed with an initiator and a chain transfer agent, and a one-step controlled free radical copolymerization reaction is carried out at 40°C to 100°C; or, Under an inert atmosphere, the first reaction unit, the second reaction unit, and the third reaction unit are mixed with an initiator and a catalyst, and a one-step controllable free radical copolymerization reaction is carried out at 40℃~100℃.

8. The method for preparing a single battery cell according to claim 6, characterized in that, The controlled polymerization method includes atom transfer radical polymerization or reversible addition-fragmentation chain transfer polymerization.

9. The method for preparing a battery cell according to claim 8, characterized in that, The atom transfer radical polymerization method includes: The first reaction unit, the second reaction unit, and the third reaction unit are dissolved in a solvent, an initiator and a catalyst are added, and the reaction is carried out in an inert atmosphere at 40°C to 100°C.

10. The method for preparing a battery cell according to claim 1, characterized in that, The adhesive also includes additives.

11. The method for preparing a battery cell according to claim 1, characterized in that, The negative electrode active material includes silicon-based active materials.

12. The method for preparing a battery cell according to claim 1, characterized in that, The formation step includes: performing an initial charge and discharge at a rate of 0.05C to 0.2C.

13. A single battery cell, characterized in that, It is obtained by the preparation method described in any one of claims 1 to 12.

14. A battery device, characterized in that, The battery device includes one or more of the following: battery cell as described in claim 13, battery device including battery module, battery pack, energy storage battery.

15. An electrical appliance, characterized in that, The electrical device includes the battery device as described in claim 14, the battery device being used to provide electrical energy.

16. An energy storage device, characterized in that, The energy storage device includes the battery device as described in claim 14, the battery device being used to store electrical energy.

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