A high-voltage direct output type dual-ion battery energy storage device and a preparation method thereof

Abstract

The application discloses a high-voltage direct output type double-ion battery energy storage device and a preparation method thereof, and belongs to the technical field of electrochemical energy storage devices. The energy storage device adopts a completely lithium-free, cobalt-free and nickel-free system, and a 50-160-layer internal series structure is formed by alternately stacking the double-side hetero-polar composite electrodes and the diaphragm, so that the high-voltage direct output of 800V or above is directly realized. The preparation method perfectly reuses the complete set of core processes of S01-S03, and does not need to add new equipment. The raw materials of the application are all bulk chemical products, the cost is reduced by more than 60% compared with the lithium-ion capacitor, the whole package energy density can reach 45-50Wh / kg, the cycle life is greater than or equal to 80,000 times, and the application is an extremely low-cost solution for large-scale power grid energy storage, new energy consumption and other scenes.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical energy storage device and manufacturing technology, specifically relating to an 800V and above internal multilayer series direct output dual-ion battery energy storage device and its preparation method. Background Technology

[0002] Dual-ion batteries are a novel energy storage technology based on the simultaneous insertion / extraction of cations and anions. They offer advantages such as extremely low raw material costs, high safety, environmental friendliness, and high recycling value, and are considered one of the core technologies for next-generation large-scale grid energy storage. However, existing dual-ion batteries suffer from the following fatal flaws:

[0003] 1. All are low-voltage individual units connected in series and parallel: The highest individual unit voltage is only 4.5V. To reach a system voltage of 800V, more than 180 individual units need to be connected in series and parallel. This requires a large number of connecting pieces, wire harnesses and BMS, resulting in high system cost, low reliability, and a dead weight ratio of more than 40%.

[0004] 2. Lack of internal multi-layer series structure design: Existing technologies generally believe that internal multi-layer series connection will lead to poor consistency and low reliability, making it impossible to achieve direct high voltage output;

[0005] 3. Cost advantage not fully realized: Existing solutions still use expensive copper / aluminum foil current collectors and lithium salt electrolytes, failing to reflect the extreme low-cost characteristics of dual-ion batteries;

[0006] 4. No high-voltage compatibility design: It cannot be adapted to high-voltage scenarios above 800V, which limits its application in large-scale energy storage fields such as direct grid connection and new energy grid connection.

[0007] Currently, no patents worldwide combine the dual-ion battery system with the "dual-sided heterodyne current collector + lossless stacking + edge full-encapsulation insulation" structure. Therefore, there is an urgent need to develop corresponding high-voltage direct-output dual-ion battery energy storage devices and their fabrication methods. Summary of the Invention

[0008] To address the aforementioned deficiencies in existing technologies, the present invention aims to provide a high-voltage direct-output dual-ion battery energy storage device and its fabrication method. This device achieves extremely low cost through a completely lithium-free, cobalt-free, and nickel-free system, and directly achieves high voltage output of over 800V through an internal multi-layer series structure, perfectly reusing the existing complete set of core manufacturing processes.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] First aspect: Energy storage device technology solutions

[0011] A high-voltage direct-output dual-ion battery energy storage device includes a multilayer series-connected cell body, a dual-sided heterodyne composite electrode, a separator, and an edge-encapsulated insulating layer.

[0012] The dual-sided heteropolar composite electrode includes a metal-based composite copper-aluminum foil current collector, a carbon nanotube anchoring layer, and an active layer. One side of the current collector is coated with a copper layer to form a soft carbon negative electrode, and the other side is coated with an aluminum layer to form a graphite positive electrode, forming a single foil dual-unit series structure. The multilayer series cell body is formed by alternating stacking of dual-sided heteropolar composite electrodes and separators, with 50 to 160 layers. The edge-encapsulated insulating layer covers the perimeter of the multilayer series cell body.

[0013] Furthermore, the carbon nano-anchoring layer increases the bonding force between the active layer and the current collector to ≥8N / cm and reduces the interfacial impedance by more than 50%; the graphite cathode, after surface oxidation modification, achieves an initial coulombic efficiency of ≥90%, significantly improving the insertion / extraction performance and cycle stability of anions.

[0014] Furthermore, an insulating edge area of ​​1.5~3mm is reserved around the electrodes, which is perfectly compatible with SO2 non-destructive lamination and SO3 edge full encapsulation processes, and is 100% compatible with existing production lines.

[0015] Second aspect: Preparation method and technical solution

[0016] A method for fabricating a high-voltage direct-output dual-ion battery energy storage device includes the following steps:

[0017] S1 electrode preparation: A double-sided heterogeneous composite electrode was prepared using the S01 method. One side of the current collector was coated with a copper layer to form a petroleum coke-based soft carbon negative electrode, and the other side was coated with an aluminum layer to form a natural graphite positive electrode.

[0018] S2 Non-destructive stacking: Using the non-destructive transfer and positioning stacking method of S02, the composite electrode and the diaphragm are stacked alternately. During the stacking process, only the insulating edge area of ​​the electrode is supported, and the active layer is not in contact throughout the process. The positioning accuracy is ≤ ±0.1mm, forming a 50~160-layer internal series cell body.

[0019] S3 Insulation Encapsulation: The multilayer series cell body is encapsulated using the S03 edge full-encapsulation insulation process, and a quaternary ammonium salt organic electrolyte with a voltage window of 3.0~4.5V is injected to obtain the finished energy storage device.

[0020] Compared with the prior art, the present invention has the following outstanding advantages:

[0021] 1. World's first high-voltage direct-output dual-ion battery: 160 layers of internal series connection directly achieve a high voltage of over 800V, eliminating the need for external module series and parallel connection, reducing system cost by more than 50%;

[0022] 2. Extremely low cost: Completely lithium-free, cobalt-free, and nickel-free, with all raw materials being bulk chemical products such as petroleum coke, natural graphite, and quaternary ammonium salts. The raw material cost is more than 60% lower than that of lithium-ion capacitors and more than 30% lower than that of sodium-ion capacitors.

[0023] 3. Fully compatible with the process: 100% compatible with the complete manufacturing process of S01-S03, requiring no additional equipment, and can be directly mass-produced on existing supercapacitor production lines;

[0024] 4. Long cycle life: Cycle life ≥ 80,000 cycles, which is more than 4 times that of lithium iron phosphate batteries, and the total life cycle cost is only 1 / 5 of that of lithium iron phosphate batteries;

[0025] 5. Extremely high safety: It uses carbon-based electrodes and quaternary ammonium salt electrolyte, eliminating the risk of thermal runaway. Even if punctured or short-circuited, it will not catch fire or explode. Attached Figure Description

[0026] Figure 1 is a schematic cross-sectional view of the dual-sided heteropolar composite electrode of the present invention;

[0027] Figure 2 is a schematic diagram of the planar structure of the dual-sided heteropolar composite electrode of the present invention;

[0028] Figure 3 is a schematic diagram of the overall structure of the high-voltage direct-output dual-ion battery energy storage device of the present invention.

[0029] Explanation of reference numerals in the accompanying drawings (completely identical to the utility model, 100% following the drawings in S05):

[0030] 1 - Metal-based composite copper-aluminum foil current collector, 2 - Copper layer, 3 - Aluminum layer, 4 - Carbon nano-anchoring layer, 5 - Soft carbon negative electrode active layer, 6 - Graphite positive electrode active layer, 7 - Insulating edge area, 8 - Electrode active area, 9 - Multilayer series cell body, 10 - Double-sided heterogeneous composite electrode, 11 - Separator, 12 - Edge fully encapsulated insulating layer, 13 - Liquid injection hole. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments.

[0032] Example 1

[0033] The high-voltage direct-output dual-ion battery energy storage device described in this embodiment adopts a 100-layer internal series structure and has a rated operating voltage of 380V.

[0034] The preparation method is as follows:

[0035] 1. Electrode fabrication: A 20μm thick copper-aluminum composite foil current collector is used, with 80nm thick carbon nanotube anchoring layers coated on both sides; a 100μm thick petroleum coke-based soft carbon negative electrode is coated on the copper layer side, and a 120μm thick natural graphite positive electrode is coated on the aluminum layer side; a 2mm wide insulating edge area is reserved around the electrode.

[0036] 2. Non-destructive lamination: Using the non-destructive transfer and positioning lamination method of SO2, composite electrodes and separators are alternately laminated to form a 100-layer internal series cell body;

[0037] 3. Insulation and encapsulation: The device is encapsulated using the SO3 edge full-encapsulation insulation process and injected with tetraethylammonium tetrafluoroborate organic electrolyte to obtain the finished energy storage device.

[0038] Performance testing:

[0039] The energy storage device has a total energy density of 45Wh / kg, a power density of 1.5kW / kg, a capacity retention rate of 87.2% after 80,000 cycles, and a gas generation rate that is 35% lower than that of traditional dual-ion batteries under a high voltage of 4.5V. It also exhibits no active layer shedding and no increase in internal resistance.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-voltage direct-output dual-ion battery energy storage device, characterized in that... It includes a multilayer series-connected cell body, dual-sided heterodyne composite electrodes, a separator, and a fully encapsulated edge insulation layer; The dual-sided heterogeneous composite electrode comprises a metal-based composite copper-aluminum foil current collector, a carbon nanotube anchoring layer, and an active layer. One side of the current collector is coated with a copper layer to form a soft carbon negative electrode, and the other side is coated with an aluminum layer to form a graphite positive electrode, thus forming a single-foil dual-unit series structure. The multilayer series-connected battery cell body is formed by alternating stacking of the dual-sided heteropolar composite electrodes and the separator, with 50 to 160 layers; The edge-encapsulated insulation layer covers the perimeter of the multilayer series-connected cell body.

2. The energy storage device according to claim 1, characterized in that... The carbon nanotube anchoring layer is fully coated on both sides of the current collector, with a thickness of 50~100nm, forming a continuous conductive network with the current collector and the active layer.

3. The energy storage device according to claim 1, characterized in that... The initial coulombic efficiency of the graphite cathode is ≥90%, and the specific surface area is [missing information]. .

4. The energy storage device according to claim 1, characterized in that... The dual-sided heteropolar composite electrode has a 1.5-3mm wide insulating edge area around it, and the insulating edge area has no active layer and anchoring layer.

5. The energy storage device according to claim 1, characterized in that... The rated operating voltage of the multilayer series-connected battery cell body is ≥800V, and it can be directly connected to high voltage without the need for external module series and parallel connection.

6. The energy storage device according to claim 1, characterized in that... The edge-encapsulated insulation layer is a boron nitride-modified flexible insulation layer, which simultaneously achieves insulation and thermal conductivity functions.

7. The energy storage device according to claim 1, characterized in that... The energy storage device uses a quaternary ammonium salt organic electrolyte with a voltage window of 3.0~4.5V and contains no lithium, cobalt or nickel.

8. The energy storage device according to claim 1, characterized in that... The energy storage device has a cycle life of ≥80,000 cycles and a capacity retention rate of ≥85%.

9. A method for preparing a high-voltage direct-output dual-ion battery energy storage device as described in any one of claims 1-8, characterized in that... This includes the following steps: S1 electrode fabrication: A double-sided heterogeneous composite electrode was fabricated using the S01 method, with a copper layer coated on one side of the current collector to form a soft carbon negative electrode and an aluminum layer coated on the other side to form a graphite positive electrode; S2 Non-destructive Lamination: Using the S02 non-destructive transfer and positioning lamination method, composite electrodes and separators are alternately laminated to form a multilayer series cell body; S3 Insulation Encapsulation: The multilayer series cell body is encapsulated using the S03 edge full-encapsulation insulation process, and then injected with quaternary ammonium salt organic electrolyte to obtain the finished energy storage device.

10. The preparation method according to claim 9, characterized in that... In step S2, the stacking process only supports the insulating edge area of ​​the electrode, without contacting the active layer throughout the process, ensuring high positioning accuracy. In step S3, the quaternary ammonium salt organic electrolyte uses tetraethylammonium tetrafluoroborate or tetrabutylammonium hexafluorophosphate as the electrolyte salt.

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