A high-voltage straight-out lithium ion capacitor energy storage device and a preparation method thereof
By employing an internal multi-layer series structure and a non-contact pre-lithiation process, combined with non-destructive stacking and edge full encapsulation, the problems of high-voltage direct output and pre-lithiation damage in lithium-ion capacitor devices have been solved. This has enabled the fabrication of highly efficient high-voltage direct output lithium-ion capacitor devices, reducing system costs and improving energy density and cycle life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGXI QINZHOU HUAYUAN ELECTRONICS CO LTD
- Filing Date
- 2026-04-10
- Publication Date
- 2026-05-29
AI Technical Summary
Existing lithium-ion capacitors cannot achieve direct high voltage output, resulting in poor consistency, low reliability, and high system costs. Furthermore, the pre-lithiation process can easily damage the electrodes, and there is a lack of system-level solutions.
It adopts an internal multi-layer series structure, dual-sided heterogeneous composite electrodes and edge-encapsulated insulation layer, combined with non-contact pre-lithiation and non-destructive stacking process to form a 50-380 layer series cell body, and is packaged through edge-encapsulated insulation process to achieve high voltage output above 800V.
It achieves a system cost reduction of over 40% for high-voltage direct-output lithium-ion capacitors, an energy density increase of over 30%, a cycle life increase to 100,000 cycles, a yield increase to 95%, and 100% compatibility with existing manufacturing processes.
Smart Images
Figure CN122117650A_ABST
Abstract
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 lithium-ion capacitor energy storage device and its preparation method. Background Technology
[0002] Lithium-ion capacitors (LICs) combine the high power and long cycle life of supercapacitors with the high energy density of lithium batteries, making them an ideal choice for grid-connected energy storage and industrial high-voltage backup applications. However, existing lithium-ion capacitors suffer from the following fatal flaws:
[0003] 1. All are low-voltage individual units connected in series and parallel: The highest module voltage does not exceed 150V, requiring a large number of connecting pieces, wire harnesses and BMS, resulting in high system cost, low reliability, and a dead weight ratio of 30% to 40%;
[0004] 2. Lack of internal multi-layer series structure design: High voltage direct output cannot be achieved directly. Existing technologies all believe that internal multi-layer series will lead to poor consistency and low reliability.
[0005] 3. The pre-lithiation process is incompatible with existing manufacturing methods: Existing pre-lithiation processes are all contact-type pre-lithiation, which can easily cause electrode damage and powder shedding, resulting in low yield and high cost;
[0006] 4. Lack of system-level solutions: Existing patents only protect the pre-lithiation process or electrode materials individually, without a complete system design for high-voltage series scenarios.
[0007] Currently, no patents worldwide combine the lithium-ion capacitor 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 lithium-ion capacitor 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 lithium-ion capacitor energy storage device and its fabrication method. This device achieves direct output of high voltages above 800V through an internal multi-layer series structure, perfectly reusing the existing complete set of core manufacturing processes and significantly reducing system costs.
[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 lithium-ion capacitor 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 heterogeneous 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 containing a pre-lithiated hard carbon anode, and the other side is coated with an aluminum layer containing an activated carbon cathode, forming a single-foil dual-unit series structure. The multilayer series cell body is formed by alternating stacking of dual-sided heterogeneous composite electrodes and separators, with 50 to 380 layers. An edge-encapsulated insulating layer covers the perimeter of the multilayer series cell body.
[0013] Furthermore, the carbon nanotube 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 first coulombic efficiency of the pre-lithiated hard carbon anode is ≥92%, which significantly improves the energy density of the device.
[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 lithium-ion capacitor energy storage device includes the following steps:
[0017] S1 electrode preparation: A double-sided heterogeneous composite electrode was prepared using the S01 method, with a copper layer coated on one side of the current collector to form a hard carbon negative electrode and an aluminum layer coated on the other side to form an activated carbon positive electrode;
[0018] S2 Pre-lithiation treatment: The hard carbon anode is pre-lithiated using a non-contact electrochemical pre-lithiation method, with the pre-lithiation degree controlled at 30%~70% to avoid electrode damage during the pre-lithiation process.
[0019] S3 Non-destructive stacking: Using the non-destructive transfer and positioning stacking method of S02, the pre-lithiated composite electrode and the separator 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 50~380-layer internal series cell body.
[0020] S4 Insulation Packaging: The multilayer series cell body is packaged using the edge full-encapsulation insulation process of S03, and lithium salt organic electrolyte with a voltage window of 1.5~3.8V is injected to obtain the finished energy storage device.
[0021] Compared with the prior art, the present invention has the following outstanding advantages:
[0022] 1. World's first internal multi-layer series high voltage direct output LIC: More than 50 internal series layers directly achieve high voltage of 800V or above, without the need for external module series and parallel connection, reducing system cost by more than 40% and increasing system energy density by more than 30%;
[0023] 2. Significantly improved energy density: The overall energy density can reach 70~80Wh / kg, which is 8~10 times that of traditional supercapacitors and close to the level of lithium iron phosphate batteries;
[0024] 3. Non-destructive pre-lithiation process: Non-contact electrochemical pre-lithiation is perfectly compatible with non-destructive stacking process, avoiding electrode damage during pre-lithiation and improving yield to over 95%;
[0025] 4. Fully compatible with the process: 100% compatible with the complete manufacturing process of S01-S03, requiring no additional equipment and enabling rapid mass production;
[0026] 5. Long cycle life: Cycle life ≥ 100,000 cycles, which is more than 5 times that of lithium batteries, and the total life cycle cost is only 1 / 3 of that of lithium batteries. Attached Figure Description
[0027] Figure 1 is a schematic cross-sectional view of the dual-sided heteropolar composite electrode of the present invention;
[0028] Figure 2 is a schematic diagram of the planar structure of the dual-sided heteropolar composite electrode of the present invention;
[0029] Figure 3 is a schematic diagram of the overall structure of the high-voltage direct-output lithium-ion capacitor energy storage device of the present invention.
[0030] Explanation of reference numerals in the attached figures:
[0031] 1 - Metal-based composite copper-aluminum foil current collector, 2 - Copper layer, 3 - Aluminum layer, 4 - Carbon nano-anchoring layer, 5 - Pre-lithiated hard carbon negative electrode active layer, 6 - Activated carbon 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
[0032] The present invention will be further described in detail below with reference to specific embodiments.
[0033] Example 1
[0034] The high-voltage direct-output lithium-ion capacitor energy storage device described in this embodiment adopts a 100-layer internal series structure and has a rated operating voltage of 380V.
[0035] The preparation method is as follows:
[0036] 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 hard carbon negative electrode is coated on the copper layer side, and a 120μm thick activated carbon positive electrode is coated on the aluminum layer side; a 2mm wide insulating edge area is reserved around the electrode.
[0037] 2. Pre-lithiation treatment: A non-contact electrochemical pre-lithiation method is used to pre-lithiate the hard carbon anode at a current density of 0.2C and a temperature of 30℃, with a pre-lithiation degree of 50%.
[0038] 3. Non-destructive stacking: Using the non-destructive transfer and positioning stacking method of SO2, the pre-lithiated composite electrode and the separator are stacked alternately to form a 100-layer internal series cell body;
[0039] 4. Insulation and encapsulation: The device is encapsulated using the edge full-encapsulation insulation process of SO3 and injected with lithium hexafluorophosphate organic electrolyte to obtain the finished energy storage device.
[0040] Performance testing:
[0041] The energy storage device has a total energy density of 75Wh / kg, a power density of 2.5kW / kg, a capacity retention rate of 92.3% after 100,000 cycles, and a gas production rate that is 45% lower than that of traditional LIC under a high voltage of 3.8V. It also exhibits no active layer shedding and no increase in internal resistance.
[0042] 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 lithium-ion capacitor 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 containing a pre-lithiated hard carbon anode, and the other side is coated with an aluminum layer containing an activated carbon cathode, forming a single-foil dual-unit series structure. The multilayer series battery cell body is formed by alternating stacking of the dual-sided heteropolar composite electrodes and the separator, with 50 to 380 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 prelithiation degree of the prelithiated hard carbon anode is 30%~70%, and the initial coulombic efficiency is ≥92%.
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 no external module series or parallel connection is required.
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 lithium salt organic electrolyte with a voltage window of 1.5~3.8V.
8. The energy storage device according to claim 1, characterized in that... The energy storage device has a cycle life of ≥100,000 cycles and a capacity retention rate of ≥90%.
9. A method for fabricating a high-voltage direct-output lithium-ion capacitor energy storage device as described in any one of claims 1-8, characterized in that... This includes the following steps: S1 Electrode Fabrication: A dual-sided heterogeneous composite electrode was fabricated, with a copper layer coated on one side of the current collector to form a hard carbon negative electrode and an aluminum layer coated on the other side to form an activated carbon positive electrode; S2 Pre-lithiation treatment: The hard carbon anode is pre-lithiated using an electrochemical pre-lithiation method, with the pre-lithiation degree controlled between 30% and 70%. S3 Non-destructive stacking: Using the non-destructive transfer and positioning stacking method of SO2, the pre-lithiated composite electrode and the separator are alternately stacked to form a multilayer series cell body; S4 Insulation Packaging: The multilayer series cell body is packaged using the S03 edge full-encapsulation insulation process, and lithium salt organic electrolyte is injected to obtain the finished energy storage device.
10. The preparation method according to claim 9, characterized in that... In step S2, the current density for electrochemical pre-lithiation is 0.1~0.5C, and the pre-lithiation temperature is 25~45℃. In step S3, the stacking process only supports the insulating edge area of the electrode and does not contact the active layer throughout the process, with a positioning accuracy of ≤±0.1mm.