Modulating a solid-state battery and a method of modulation

Abstract

A kind of modulation solid-state battery and modulation method, belong to metal ion solid-state battery field, structure includes in turn: positive current collector, positive material, solid electrolyte, negative material, negative current collector and net modulation electrode;Net modulation electrode needs to do electronic and ion insulation treatment, its structure is vertical and horizontal interlaced metal wire or non-metallic conductive material silk, each metal wire can be connected at node or the boundary of net modulation electrode;The charge and discharge of battery uses unique modulation method;The gradient of accelerating promoting metal ion is enhanced along the direction of displacement current, improves the migration rate and migration quantity of carrier;It can significantly reduce charging time, improve capacity, power density, and is widely used in battery industry.

Description

Technical Field

[0001] This invention belongs to the field of chemical batteries and relates to a rechargeable battery that uses metal cation carriers, which is particularly suitable for the optimization and improvement of solid-state batteries. More precisely, it relates to the structure and method for improving indicators such as fast charging time, increasing and balancing power density. Background Technology

[0002] Solid-state batteries are battery structures that follow solid-state ionics principles, using solid electrodes and solid electrolytes. Their principle is exactly the same as liquid batteries, except that the electrolyte is solid. Although solid-state batteries generally have relatively low power density, their high energy density makes them one of the ideal battery choices for electric vehicles. Liquid and solid-state lithium batteries are called rocking chair batteries by scientists. The two ends of the rocking chair are the positive and negative electrodes, with the electrolyte in the middle. Lithium ions (or other metal ions: aluminum ions, sodium ions, etc.) move back and forth between the two ends of the rocking chair; the cycle of lithium ions moving from the positive electrode to the negative electrode and back to the positive electrode constitutes one charge-discharge cycle.

[0004] The history of solid-state battery development: Since Sony introduced lithium-ion (or other metal-ion: aluminum-ion, sodium-ion, etc.) batteries containing liquid electrolytes into electronic devices in 1991, liquid lithium batteries have become one of the most mature and widely used technologies. In 2010, Toyota launched a solid-state battery with a range exceeding 1000 km. Efforts including those by Sakti3 also aim to replace traditional liquid lithium batteries with solid-state batteries. Avestor uses a polymer separator to replace the liquid electrolyte in the battery, but has yet to resolve safety issues. In January 2018, news emerged that a groundbreaking new battery technology seemed to be finally approaching reality. If successful, the new technology could meet the needs of smartphone addicts for several days and increase the driving range of electric vehicles to over 500 miles (approximately 804 km). This new technology, called solid-state battery technology, replaces the liquid electrolyte in current batteries with ceramic materials.

[0005] In January 2018, it formed an alliance with BMW, which committed to providing some form of battery component for every product it produces over the next 10 years, whether it's a traditional hybrid, plug-in electric vehicle, or battery electric vehicle (BEV). On January 9, 2021, NIO unveiled its new 150kWh solid-state battery pack. NIO electric vehicles equipped with this technology are expected to be delivered in the fourth quarter of 2022, with a range potentially exceeding 1,000 kilometers. On January 22, 2022, the Dongfeng E70 demonstration vehicle equipped with Ganfeng solid-state batteries made its debut in Xinyu, with the first batch of 50 solid-state battery demonstration vehicles officially launched into the market. The first production line of Ganfeng Lithium Battery's Phase II 10GWh new lithium battery project also officially commenced production on the same day.

[0006] In 2022, my country's power battery technology innovation capabilities continued to improve, with the maximum energy density of ternary battery systems increasing to 212Wh / kg. In the field of new energy vehicles, it is expected that all-solid-state batteries will begin to be installed in vehicles by 2027, and mass production applications are expected to be realized by 2030.

[0007] Solid-state battery technology routes: There are three main technological routes for solid-state batteries: polymer solid-state batteries, oxide solid-state batteries, and sulfide solid-state batteries. Among them, sulfide electrolytes have the greatest development potential in all-solid-state batteries. An ideal solid-state electrolyte material should possess high ionic conductivity, chemical and electrochemical stability against lithium metal, effectively suppress lithium dendrite formation, have low manufacturing costs, and not require the use of rare metals. However, currently, each of the three technological routes has its own advantages and disadvantages, and none can simultaneously meet all the above requirements, indicating that technological breakthroughs remain challenging. In summary, sulfide electrolytes have the greatest development potential in all-solid-state batteries. The four major technological advantages of solid-state batteries: Advantage 1: Lightweight – High Energy Density. The use of an all-solid-state electrolyte changes the applicable material system for lithium-ion batteries. A key aspect is that it eliminates the need for lithium-intercalated graphite anodes; instead, metallic lithium can be used directly as the anode. This significantly reduces the amount of anode material used, resulting in a substantial increase in the overall battery energy density.

[0008] Advantage Two: Thinness – Small Size. Traditional lithium-ion batteries require separators and electrolytes, which together account for nearly 40% of the battery's volume and 25% of its mass. However, if these are replaced with solid-state electrolytes (mainly organic and inorganic ceramic materials), the distance between the positive and negative electrodes (traditionally filled by separators and electrolytes, now filled by solid-state electrolytes) can be shortened to only a few to a dozen micrometers. This significantly reduces the battery's thickness—therefore, all-solid-state battery technology is an essential path to battery miniaturization and thin-film technology.

[0009] Advantage 3: The prospect of flexibility. Even brittle ceramic materials can often be bent when their thickness is reduced to below the millimeter level, becoming flexible. Correspondingly, the flexibility of all-solid-state batteries will also be significantly improved after they become thinner and lighter. By using appropriate encapsulation materials (not rigid shells), the batteries can withstand hundreds to thousands of bends while maintaining essentially no performance degradation.

[0010] Advantage 4: Safer. Traditional lithium batteries may pose the following dangers: (1) Lithium dendrites may form when operating under high current, which could puncture the separator and cause a short circuit. (2) The electrolyte is an organic liquid, which is prone to side reactions, oxidation, decomposition, gas generation, and combustion at high temperatures. By adopting all-solid-state battery technology, these problems can be directly solved.

[0011] The four major technological bottlenecks of solar cells: Bottleneck 1 – Insufficient Electrolyte Material Performance: Solid electrolytes generally have lower ionic conductivity than liquid electrolytes, resulting in high internal resistance and low charge / discharge efficiency. Although sulfide electrolytes have high conductivity (10⁻² S / cm), they have poor chemical stability and are prone to side reactions with the positive and negative electrodes; oxide electrolytes have excellent mechanical properties, but poor interfacial contact and require high-temperature sintering processes.

[0012] Bottleneck Two – Solid-Solid Interface Contact Challenges: Poor solid-solid interface contact between electrodes and electrolytes in solid-state batteries leads to decreased lithium-ion transport efficiency and shortened cycle life. Furthermore, the lithium dendrite problem remains unresolved, potentially posing a short-circuit risk.

[0013] Bottleneck 3 – Heat dissipation and low-temperature performance: The heat generated during high-power fast charging is difficult to dissipate effectively, and the performance of solid-state batteries degrades significantly in low-temperature environments (capacity retention is less than 50% at -20℃). There is currently no economical and efficient solution.

[0014] Bottleneck Four – High Manufacturing Costs: The current production cost of solid-state batteries is 3-5 times that of traditional lithium batteries, mainly due to the high cost of special process equipment (such as dry electrodes and high-pressure sintering) and materials (such as high-purity sulfide electrolytes). For example, the large-scale production of sulfide solid electrolyte powder is still in the pilot stage, with a price as high as 500,000 yuan per ton. Summary of the Invention

[0015] The purpose of this invention is to address the shortcomings of existing technologies and fundamentally improve the structure and operation of existing solid-state batteries to overcome the four major technical bottlenecks of solid-state batteries and achieve near-limit parameters: lower equivalent internal resistance, higher energy density, and shorter charging time.

[0016] The features of this invention are: using displacement current to overcome the contact problem of metal ions (such as lithium ions) passing through solid-solid interfaces, accumulating a local concentration gradient along the migration direction required by the metal ions at that time, and actively improving the transport efficiency of lithium ions.

[0017] The technical solution of the present invention is as follows: A type of modulated solid-state battery: The structure of the modulated solid-state battery includes, in sequence: a positive current collector, a positive electrode material, a solid electrolyte, a negative electrode material and a negative current collector; and a mesh modulated electrode inserted into the positive electrode material, the solid electrolyte, and the negative electrode material; The installation characteristics of the mesh modulation electrode are as follows: a mesh modulation electrode is installed inside and on the surface of the positive electrode material, solid electrolyte, and negative electrode material. The surface of the mesh modulation electrode is parallel to the electrolyte and current collector. The structure of the mesh modulation electrode is a crisscrossing metal wire or non-metallic conductive material wire. The individual metal wires can be connected at nodes or at the boundaries of the mesh modulation electrode, which is an electrical connection. However, the mesh modulation electrode needs to be insulated from electrons and ions, which means that an insulating layer is attached to the surface of the metal wires.

[0018] The wiring arrangement of the mesh modulation electrode is either crisscrossed or simply vertical or horizontal, which saves material and increases the duty cycle of the pore area, thereby reducing the area that hinders ion passage.

[0019] A modulation method for solid-state batteries; This is a method for using modulated solid-state batteries. During charging, the positive and negative current collectors are connected to the positive and negative terminals of the charging power supply, respectively. An isolation level generating device is then connected to the mesh modulation electrode (the isolated isolation level generating device is in a high impedance state with each layer of the battery, with no electrical circuit path, and the mesh modulation electrode does not generate an additional electric field between itself and the layers of the battery). A modulation level is sent to the mesh modulation electrode, and the displacement current generated by the additional electric field points towards the negative electrode material. The additional electric field passes through the solid-solid interface between the positive electrode material and the negative electrode material and the solid electrolyte in sequence, or passes through the solid electrolyte alone. This results in an increase in ion concentration, which is more conducive to metal ions crossing the mesh modulation electrode interface. This accelerates and enhances the gradient of metal ions along the direction of the displacement current, increasing the migration rate and the number of carriers. When the modulated solid-state battery is connected to a load for discharge, the connected isolation level generation device sends a modulation level to the mesh modulation electrode; the displacement current of the additional electric field it generates points towards the positive electrode material, and the additional electric field passes through the negative electrode material, solid electrolyte and positive electrode material in sequence, as well as the solid-solid interface between each material, or passes through the solid electrolyte alone; the resulting increase in ion concentration is more conducive to metal ions crossing the mesh modulation electrode interface, thereby increasing the migration rate and the number of carriers.

[0020] Furthermore: the mesh modulation electrode can be a 2-electrode mode or a 3-electrode mode; in the 2-electrode mode, the mesh modulation electrodes are placed in the positive electrode material and the negative electrode material, or on the surface of the electrolyte; in the 3-electrode mode, the 3 mesh modulation electrodes are located inside the positive electrode material, the solid electrolyte and the negative electrode material, respectively, and connected to the isolation level generation device, so that displacement current is generated in segments between the 3 mesh modulation electrodes.

[0021] Furthermore: The isolation level generation device sends a modulation level to the mesh modulation electrode, and the generated displacement current (electric field strength) continuous waveform, or (transient) pulse waveform, DC pulsating waveform is beneficial to increase.

[0022] Furthermore: It can be used not only in solid-state batteries but also in liquid electrolyte batteries. Beneficial features of the present invention: It accelerates the migration of charge carriers (lithium ions (or other metal ions: aluminum ions, sodium ions, etc.)) to the positive and negative electrodes, which is equivalent to improving and reducing internal resistance; it also has the advantages of faster charging, larger current discharge, and expanded capacity. Attached Figure Description

[0023] Figure 1 Schematic diagram of a typical solid-state battery structure (cross-section) Figure 2 Schematic diagram of the mesh modulation electrode structure Figure 3 Schematic diagram of solid-state battery structure and discharge process (cross-sectional view) Figure 4 Schematic diagram of solid-state battery structure and charging process (cross-sectional view) Figure 5 Schematic diagram of the position and state of the modulation electrode in a modulated solid-state battery (cross-sectional view). Label Explanation: 1. Cathode material 2. Negative electrode material 3. Solid electrolyte 4. Modulation of solid-state batteries 5. Load 6. Positive current collector 7. Negative current collector 8. Mesh modulation electrode 9. Displacement current 1 10. Isolation Level Generation Device 11. Mesh modulation electrode A 12. Mesh modulation electrode B 13. Insulation layer (similar to enameled wire) 14. Modulation level 1 15. Modulation level 2 16. Charging power supply 17. Modulation level 3 18. Modulation level 4 19. Direction of electron movement 1 20. Direction of electron movement 2 21. Displacement current 2 22. Metal wire 23. Metal ions 24. Two-electrode modulation mode 25. 3-electrode modulation mode 26. Border 28. Enlarged view of a specific area 29. Electrode wire 30. Lead wire 31. Single-row wire mesh [Specific Implementation Case] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings: like Figure 1 As shown: The layered structure of a typical solid-state battery includes, in sequence: a positive electrode current collector (6), a positive electrode material (1), a solid electrolyte (3), a negative electrode material (2), and a negative electrode current collector (7). (Sometimes, the negative electrode material and the negative electrode current collector are made of the same material, for example, lithium metal can be used as both materials).

[0024] The traditional charging process is as follows: the positive current collector (6) is connected to the positive terminal of the power supply, and the negative current collector (7) is connected to the negative terminal of the power supply. Under the electric field force between the current collectors driven by the electromotive force of the external power supply, the electrons lost by the metal atoms in the positive electrode material (1) flow through the positive current collector (6) and the external circuit to the negative current collector (7) and then embed into the negative electrode material (2) (which can be embedded in the graphite lattice); on the other hand, the metal ions precipitated from the positive electrode material (1) migrate and pass through the solid electrolyte (3) under the dual action of the electric field force and diffusion force (diffusion force of concentration gradient) between the current collectors to reach and embed into the region of the negative electrode material (2) (which can be embedded in the graphite lattice or directly generate metal in the negative electrode region). When most of the region of the negative electrode material (such as the graphite lattice) is filled with (electrons and ions), the charging process is completed.

[0025] The traditional discharge process is as follows: when the external circuit is closed by the load, the negative electrode region sends electrons to the external circuit through the negative electrode current collector (7) and back to the positive electrode material (1) through the positive electrode current collector (6). At the same time, lithium ions migrate from the negative electrode material (2) through the solid electrolyte (3) back to the positive electrode material (1) and return to the positive electrode binding state before charging.

[0026] From an energy conversion perspective, the binding energy of lithium ions and electrons in the negative electrode material region is greater than that in the positive electrode material. Both solid and liquid electrolytes have the characteristic of isolating electron flow, so electron migration in the battery can only occur through the external circuit, resulting in an extremely low discharge rate. However, the battery's charging time, discharge current, electrolyte ionic conductivity, and the degree of contact between the electrode material and the solid-solid interface all play a role.

[0027] like Figure 2 , Figure 3 , Figure 4 As shown: like Figure 2 As shown: The structure of the mesh modulation electrode (8) is a crisscrossing metal wire (22) or non-metallic conductive material wire. Figure 2 The image shown is from the front; (from the side) it appears as a thin, sheet-like structure that forms a mesh.

[0028] The nodes of each metal wire are welded, bonded, or directly processed as a whole, which can maintain the electrical conductivity at the nodes, or only the frame (26) can be electrically conductive, keeping the whole net as an equipotential body.

[0029] Due to the large area of ​​the vias in the mesh modulation electrode (8), the migration of metal ions is not hindered. The mesh modulation electrode A (11) and the mesh modulation electrode (8) need to be insulated. An insulating layer (13) similar to that of enameled wire is attached to the surface of the metal wire (22) (i.e., to isolate both electrons and ions), as shown in the enlarged view (28) of the electrode wire (29).

[0030] The purpose is to avoid the free exchange of electrons and ions with the positive electrode, negative electrode material and electrolyte of the battery. Only displacement current 1 (9) and displacement current 2 (21) are allowed to exist, so as to avoid the chance of the migrating metal ions combining with electrons. The lead (30) is used to connect with the external electronic control system.

[0031] In addition to crisscrossing metal wires, a single longitudinal or transverse metal wire structure is also an option, which is characterized by material saving and larger gaps; as shown in the schematic diagram of the mesh modulation electrode of the single row wire mesh (31) below.

[0032] exist Figure 3 , Figure 4As can be seen from the diagram of the cross-sectional structure of the modulated solid-state battery (4): the mesh modulation electrode A (11) and the mesh modulation electrode B (12) are embedded in the positive electrode material and the negative electrode material, and the mesh surface is parallel to the surface of the positive and negative electrode materials; in order to obtain a good boosting driving effect, the distance between the mesh modulation electrode A (11) and the mesh modulation electrode B (12) and the electrolyte surface is relatively small relative to the thickness of the positive and negative electrode materials, which is equivalent to 0%-80% of the thickness of the positive and negative electrode material layers. The meaning of 0% is that the modulation electrode can be directly covered on the surface of the solid electrolyte or electrode layer.

[0033] The working principle of the modulated solid-state battery (4): The charging and discharging processes are basically the same as those of ordinary batteries. The difference is that when the charging power supply (16) discharges (electron running direction 2 (20)), the isolation level generating device (10) sends modulation level 3 (17) and modulation level 4 (18) to the mesh modulation electrode A (11) and the mesh modulation electrode A (10); the so-called isolation refers to the power ground of the isolation level generating device (10) being isolated from the power ground of the charging power supply (16) (high resistance state: this can be achieved by using an isolation transformer); in this way, a displacement current is generated between the mesh modulation electrode A (11) and the mesh modulation electrode B (12), and there is no additional electric field or displacement current between the mesh modulation electrode A (11) and the mesh modulation electrode B (12) and the positive and negative current collectors of the battery; the displacement current 2 (21) during charging points towards the negative electrode material, which will generate an additional electric field force on the metal ions (since the value of the additional electric field can be relatively large, and it is mainly applied to the solid electrolyte, a large electric field will not cause damage). In addition to the conventional steady level, the pulsating DC level can force metal ion carriers to pass through the solid-solid interface barrier in the resonant mode, and pass through the solid-solid interface between the positive electrode material (1) and the negative electrode material (2) and the solid electrolyte (3) in sequence (overcoming contact resistance and contact isolation gap), resulting in an increase in ion concentration, which is more conducive to metal ions passing through the mesh modulation electrode interface.

[0034] The modulation levels 3 (17) and 4 (18) transmitted by the mesh modulation electrode A (11) are the properties of the displacement current (electric field strength and change), which can be a continuous waveform or a (transient) pulse waveform; such as a pulsating DC waveform, etc.

[0035] During the discharge process through the load (5), metal ions need to return from the negative electrode material to the positive electrode material under the action of the plate electric field force (the direction of electron movement in the circuit is 1 (19)); at this time, the isolation level generating device (10) sends modulation level 1 (14) and modulation level 2 (15) to the mesh modulation electrode A (11) and the mesh modulation electrode B (12). The discharge process is reversed compared with the charging process mentioned above; that is, the displacement current 1 (9) during discharge points to the positive electrode material, which will also sequentially generate metal ions through the solid-solid interface between the negative electrode material (2) and the positive electrode material (1) and the solid electrolyte (3), resulting in an increase in ion concentration, which is also more conducive to metal ions crossing the mesh modulation electrode interface.

[0036] Similarly, the modulation level 1 (14) and modulation level 2 (15) sent by the mesh modulation electrode B (12) are the properties of the displacement current (electric field strength and change), which can be a continuous waveform or a (transient) pulse waveform; such as a pulsating DC waveform, etc.

[0037] like Figure 5 As shown: The position of the modulation electrode in the modulated solid-state battery is shown in the cross-sectional view of the battery. The top is the mode with 2 modulation electrodes (24), and the bottom is the mode with 3 modulation electrodes (25).

[0038] The working mode of the two-electrode mode (24) is the same as above. The mesh electrode in the left figure is closer to the current collector; the one on the right is closer to the electrolyte in the middle. Since there is less positive and negative electrode material sandwiched between the mesh modulation electrodes, the modulation process requires less energy. The position and number of mesh modulation electrodes can be set as needed: the mesh modulation electrodes can be set on the surface and internal areas of the electrolyte, positive electrode material and negative electrode material, and the surface area of ​​the current collector; the metal wires of the mesh modulation electrodes are insulated so that only displacement current exists, so as to prevent electrons from participating in the exchange of metal positive ions as charge carriers.

[0039] When the isolated positive and negative voltages of the modulation electrode are as shown in this figure, under the action of displacement current 1 (9), the gradient of metal ions (23) will be accelerated and enhanced along the direction of displacement current 1 (9), thereby increasing the migration rate and the number of carriers.

[0040] In the 3-electrode modulation mode (25), the three mesh modulation electrodes (8) are located inside the positive electrode material, the solid electrolyte and the negative electrode material, respectively. The difference between the left and right figures is the relative distance between the mesh modulation electrodes and the electrolyte.

Claims

1. A modulated solid-state battery, comprising, in sequence: Positive current collector (6), positive electrode material (1), solid electrolyte (3), negative electrode material (2) and negative current collector (7); Its characteristics are: Mesh modulation electrodes are installed inside and on the surface of the positive electrode material (1), solid electrolyte (3), and negative electrode material (2). The surface of the mesh modulation electrode is parallel to the electrolyte and the current collector. The structure of the mesh modulation electrode is a crisscrossing metal wire or non-metallic conductive material wire. Each metal wire can be electrically connected at the node or the frame of the mesh modulation electrode. Mesh modulation electrodes require insulation treatment for electrons and ions, which involves attaching an insulating layer to the surface of the metal wire. The wiring arrangement of the mesh modulation electrode is either crisscrossed or simply longitudinal or transverse.

2. A modulation method for solid-state batteries; Its characteristics are as follows : This is a method for using modulated solid-state batteries. During charging, the positive and negative current collectors are connected to the positive and negative terminals of the charging power supply, respectively. An isolation level generating device (10) is connected to the mesh modulation electrode to send a modulation level to the mesh modulation electrode. The displacement current of the additional electric field generated by the device points to the negative electrode material. The additional electric field passes through the solid-solid interface between the positive electrode material (1) and the negative electrode material (2) and the solid electrolyte (3) in sequence, or passes through the solid electrolyte (3) alone. This generates an increase in ion concentration, which is more conducive to metal ions crossing the mesh modulation electrode interface. This accelerates the gradient of metal ions (23) along the direction of the displacement current 1 (9), thereby increasing the migration rate and the number of carriers. When the modulated solid-state battery is connected to the load for discharge, the connected isolation level generation device (10) sends a modulation level to the mesh modulation electrode; the displacement current of the additional electric field it generates points to the positive electrode material, and the additional electric field passes through the negative electrode material (2), solid electrolyte (3) and positive electrode material (1) in sequence, as well as the solid-solid interface between each material, or passes through the solid electrolyte (3) alone; the ion concentration increases, which is more conducive to metal ions passing through the mesh modulation electrode interface, and improves the migration rate and migration number of charge carriers.

3. A modulated solid-state battery according to claim 1, characterized in that: The mesh modulation electrode is a 2-piece modulation electrode mode (24) or a 3-piece modulation electrode mode (25). In the 2-piece modulation electrode mode (24), the mesh modulation electrodes are placed in the positive electrode material and the negative electrode material, or on the surface of the electrolyte. In the 3-piece modulation electrode mode (25), the 3 mesh modulation electrodes (8) are located inside the positive electrode material, the solid electrolyte and the negative electrode material, respectively, and are connected to the isolation level generation device. Displacement current is generated in segments between the 3 mesh modulation electrodes.

4. The modulation method for a solid-state battery according to claim 2, characterized in that: The isolation level generating device sends a modulation level to the mesh modulation electrode, generating a continuous waveform or pulse waveform of displacement current and electric field strength.

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