A bipolar lithium-ion battery material evaluation chip and a performance evaluation method thereof

Abstract

The application provides a bipolar lithium ion battery material evaluation chip and a performance evaluation method thereof, and belongs to the technical field of battery manufacturing, and comprises a substrate, which comprises an insulating base material and a conductive layer, the conductive layer is arranged on the insulating base material, the conductive layer comprises a positive electrode connecting part, an electrification part and a negative electrode connecting part, and the positive electrode connecting part, the electrification part and the negative electrode connecting part are sequentially arranged and separated from each other; an upper cover is provided with a first liquid flow channel and a second liquid flow channel, and the first liquid flow channel and the second liquid flow channel are both groove structures and are separated from each other. The application has the beneficial effects that: the micro electrochemical reaction environment of the positive electrode and the negative electrode can be simultaneously constructed on the same chip, space is saved, additional wiring is not needed, and the migration process of lithium ions between the positive electrode and the negative electrode can be truly simulated, so that the electrochemical performance of the positive electrode material and the negative electrode material in the charging and discharging process can be efficiently and accurately evaluated, and the material screening efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of battery manufacturing technology and relates to a bipolar lithium-ion battery material evaluation chip and its performance evaluation method. Background Technology

[0002] Lithium-ion batteries, as important electrochemical energy storage devices, play a crucial role in promoting energy structure transformation. They can efficiently convert the unstable electricity generated by intermittent renewable energy sources such as solar and wind power into stable and dispatchable electrical energy, and are widely used in grid energy storage, new energy vehicles, and daily life. Especially under the "dual-carbon" strategy, lithium-ion batteries significantly reduce carbon emissions and environmental pollution by reducing dependence on fossil fuels, contributing to the achievement of green and low-carbon development goals.

[0003] In the research and development process of lithium-ion batteries, the performance evaluation of electrode materials is a core step that determines the overall performance of the battery. Traditional evaluation methods mainly rely on coin cells or small pouch cells. Although they can provide some electrochemical data, they suffer from problems such as long preparation cycles, high material consumption, and low testing throughput, making it difficult to meet the needs of rapid iteration of new materials. More importantly, these methods usually require the construction of a complete positive and negative electrode pairing system, and cannot independently and synchronously analyze the intrinsic behavior of a single positive or negative electrode material in a real electrochemical environment.

[0004] Bipolar electrode technology offers a new approach to materials evaluation. As a "wireless" electrochemical configuration, the bipolar electrode itself is not directly connected to an external power source. One end acts as the anode under the drive of an electric field, undergoing an oxidation reaction, while the other end acts as the cathode, undergoing a reduction reaction, thus integrating anode and cathode functions on the same conductor. Closed-type bipolar electrodes are particularly suitable for fundamental materials research—the oxidation and reduction ends are coupled only through electronic conduction, without material exchange, effectively avoiding cross-interference from side reaction products and more realistically reflecting the electrochemical characteristics of the material itself. Furthermore, combining bipolar electrodes with microfluidic technology allows for the introduction of independent electrolyte systems at both ends, supporting dynamic electrolyte updates and providing a flexible platform for simulating complex operating conditions or screening suitable electrolytes.

[0005] However, there is a lack of a miniaturized evaluation device with a well-defined structure, high integration, and the ability to simultaneously accommodate positive and negative electrode materials and achieve closed-loop bipolar testing in the existing technology, which has great potential for improvement. Summary of the Invention

[0006] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing a bipolar lithium-ion battery material evaluation chip and its performance evaluation method.

[0007] The objective of this invention can be achieved through the following technical solution: a bipolar lithium-ion battery material evaluation chip, comprising: The substrate includes an insulating substrate and a conductive layer. The conductive layer is disposed on the insulating substrate and includes a positive electrode connection portion, a current-carrying portion and a negative electrode connection portion. The positive electrode connection portion, the current-carrying portion and the negative electrode connection portion are arranged sequentially and spaced apart from each other. The top cover is provided with a first liquid flow channel and a second liquid flow channel, both of which are tank structures and are separated from each other; The substrate is connected to the top cover, the conductive layer is located on the side of the substrate near the top cover, and the first liquid channel and the second liquid channel are located on the side of the top cover near the substrate; A first reaction cell is formed between the first liquid channel and the substrate. The first reaction cell is used to contain the first electrolyte and the negative electrode material. A portion of the positive electrode connection and a portion of the energized portion are both located in the first reaction cell. A second reaction cell is formed between the second liquid channel and the substrate. The second reaction cell is used to contain the second electrolyte and the positive electrode material. A portion of the energized part and a portion of the negative electrode connection part are located in the second reaction cell.

[0008] In the aforementioned bipolar lithium-ion battery material evaluation chip, the top cover is further provided with a first injection hole. One end of the first injection hole is located on the side of the top cover away from the substrate, and the other end of the first injection hole is connected to the first liquid flow channel.

[0009] In the aforementioned bipolar lithium-ion battery material evaluation chip, the top cover is further provided with a second injection hole. One end of the second injection hole is located on the side of the top cover away from the substrate, and the other end of the second injection hole is connected to the second liquid flow channel.

[0010] In the aforementioned bipolar lithium-ion battery material evaluation chip, the energized part is provided with a first loading region for loading negative electrode material at the position of the first reaction cell, and the energized part is provided with a second loading region for loading positive electrode material at the position of the second reaction cell.

[0011] In the aforementioned bipolar lithium-ion battery material evaluation chip, the insulating substrate is ordinary glass, and the conductive layer is a copper-plated indium tin oxide conductive layer.

[0012] In the aforementioned bipolar lithium-ion battery material evaluation chip, the top cover is configured as a polydimethylsiloxane component.

[0013] A method for evaluating the performance of positive and negative electrode materials for lithium-ion batteries includes the following steps: S1. The mold is prepared by soft photolithography and the spatial contour of the mold is transferred to the upper cover blank by imprinting process, thereby forming an upper cover with a first liquid flow channel and a second liquid flow channel that are separated from each other. S2. A conductive layer is provided on an insulating substrate, such that the conductive layer includes a positive electrode connection portion, a current-carrying portion and a negative electrode connection portion arranged sequentially and spaced apart from each other, thereby forming a substrate; S3. Load a negative electrode material in the first load area corresponding to the first liquid flow channel in the energized part, and load a positive electrode material in the second load area corresponding to the second liquid flow channel in the energized part. S4. Arrange the side of the substrate with the conductive layer opposite to the side of the top cover with the liquid flow channel. Connect the top cover to the substrate. After connection, the first liquid flow channel and the substrate enclose to form a first reaction cell. The second liquid flow channel and the substrate enclose to form a second reaction cell. A part of the positive electrode connection part and a part of the energized part are located inside the first reaction cell. A part of the energized part and a part of the negative electrode connection part are located inside the second reaction cell. S5. A first electrolyte is supplied to the first reaction tank and a second electrolyte is supplied to the second reaction tank, so that the interior of the first reaction tank is filled with the first electrolyte and the interior of the second reaction tank is filled with the second electrolyte. S6: Connect the positive electrode connection and negative electrode connection of the substrate to the electrochemical workstation or lithium battery charging and discharging equipment via wires. When a charging voltage excitation signal is applied, the solid phase of the positive electrode material in the second reaction cell undergoes a delithiation oxidation reaction, and lithium ions leave the solid phase of the positive electrode and enter the second electrolyte. The lithium ions migrate directionally along the electrolyte to the first reaction cell and are embedded in the solid phase of the negative electrode material, and the solid phase of the negative electrode material undergoes a lithium intercalation reduction reaction. When a discharge voltage excitation signal is applied, the solid phase of the negative electrode material in the first reaction cell undergoes a delithiation oxidation reaction, and lithium ions leave the solid phase of the negative electrode and enter the first electrolyte. The lithium ions migrate directionally along the electrolyte to the second reaction cell and intercalate into the solid phase of the positive electrode material, where the solid phase of the positive electrode material undergoes a lithium intercalation reduction reaction. Among them, the electrochemical workstation or lithium battery charging and discharging equipment is configured to output excitation electrical signals to the conductive layer, and simultaneously collect and store the voltage, current and impedance feedback electrical signals in the conductive circuit.

[0014] In the above-mentioned bipolar lithium-ion battery material performance evaluation method, in step S3, the negative electrode material is loaded by drop-coating the negative electrode slurry onto the first load area corresponding to the first liquid flow channel of the energized part, and the positive electrode material is loaded by drop-coating the positive electrode slurry onto the second load area corresponding to the second liquid flow channel of the energized part.

[0015] In the above-mentioned method for evaluating the performance of bipolar lithium-ion battery materials, in step S4, plasma cleaning technology is used to bond the top cover of the polydimethylsiloxane component to a common glass substrate with a copper indium tin oxide conductive layer.

[0016] In the above-mentioned method for evaluating the performance of bipolar lithium-ion battery materials, in step S5, before delivering the first electrolyte to the first reaction cell and the second electrolyte to the second reaction cell, a first injection hole is made from the side of the top cover away from the substrate and connected to the first liquid flow channel, and a second injection hole is made from the side of the top cover away from the substrate and connected to the second liquid flow channel. The first electrolyte is delivered to the first reaction cell through the first injection hole, and the second electrolyte is delivered to the second reaction cell through the second injection hole.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This bipolar lithium-ion battery material evaluation chip, by arranging the positive electrode connection part, the energized part, and the negative electrode connection part sequentially and separating them from each other, and combining them with the first liquid flow channel and the second liquid flow channel in the upper cover to form two independent reaction cells, realizes the simultaneous construction of a micro electrochemical reaction environment for the positive and negative electrodes on the same chip, saving space, eliminating the need for additional wiring, and realistically simulating the migration process of lithium ions between the positive and negative electrodes, thereby efficiently and accurately evaluating the electrochemical performance of the positive and negative electrode materials during the charge and discharge process, and improving the material screening efficiency; by setting the upper cover to communicate with the first liquid flow channel... The first injection port facilitates precise injection of electrolyte or replacement of test liquid into the first reaction cell from outside the chip, avoiding chip disassembly or damage to the sealing structure, thus improving experimental repeatability and reducing the risk of liquid leakage. A second injection port, connected to the second liquid flow channel, facilitates precise injection of electrolyte or replacement of test liquid into the second reaction cell from outside the chip, again avoiding chip disassembly or damage to the sealing structure, improving experimental repeatability and reducing liquid leakage. Together with the first injection port, it enables independent liquid management of the first and second reaction cells, supporting testing of differentiated electrolyte systems and enhancing the chip's applicability and flexibility. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the substrate for the unloaded positive electrode material and negative electrode material of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of the unperforated top cover of the present invention.

[0020] Figure 3 This is a schematic diagram of the substrate loaded with positive and negative electrode materials according to the present invention.

[0021] Figure 4 This is a schematic diagram of the structure of the present invention, in which a substrate loaded with positive and negative electrode materials is bonded to an unperforated top cover.

[0022] Figure 5 This is a schematic diagram of the structure of the bipolar lithium-ion battery material evaluation chip of the present invention.

[0023] Figure 6 This is a schematic diagram of the charging process of the bipolar lithium-ion battery material evaluation chip of the present invention.

[0024] Figure 7 This is a voltage-SOC variation graph of the bipolar lithium-ion battery material evaluation chip of the present invention during the charging process.

[0025] Figure 8 This is a voltage-SOC variation graph of the bipolar lithium-ion battery material evaluation chip of the present invention during the discharge process.

[0026] Figure 9 This is a discharge curve diagram of different materials at the same rate according to the present invention.

[0027] In the figure, 100 is the substrate; 110 is the insulating substrate; 120 is the conductive layer; 121 is the positive electrode connection part; 122 is the energized part; 123 is the negative electrode connection part; 124 is the first load area; 125 is the second load area; 200 is the top cover; 210 is the first liquid flow channel; 220 is the second liquid flow channel; 230 is the first injection hole; 240 is the second injection hole; 300 is the negative electrode material; and 400 is the positive electrode material. Detailed Implementation

[0028] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.

[0029] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0030] Furthermore, in this invention, descriptions involving terms such as "first," "second," and "a" are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0033] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0034] like Figures 1 to 5 As shown, a bipolar lithium-ion battery material evaluation chip includes: The substrate 100 includes an insulating substrate 110 and a conductive layer 120. The conductive layer 120 is disposed on the insulating substrate 110. The conductive layer 120 includes a positive electrode connection portion 121, a current-carrying portion 122 and a negative electrode connection portion 123. The positive electrode connection portion 121, the current-carrying portion 122 and the negative electrode connection portion 123 are arranged sequentially and spaced apart from each other. The top cover 200 is provided with a first liquid flow channel 210 and a second liquid flow channel 220. The first liquid flow channel 210 and the second liquid flow channel 220 are both tank structures and are separated from each other. The substrate 100 is connected to the top cover 200, the conductive layer 120 is located on the side of the substrate 100 near the top cover 200, and the first liquid channel 210 and the second liquid channel 220 are located on the side of the top cover 200 near the substrate 100. A first reaction cell is formed between the first liquid flow channel 210 and the substrate 100. The first reaction cell is used to contain the first electrolyte and the negative electrode material 300. A portion of the positive electrode connection portion 121 and a portion of the energized portion 122 are both located in the first reaction cell. A second reaction cell is formed between the second liquid flow channel 220 and the substrate 100. The second reaction cell is used to contain the second electrolyte and the positive electrode material 400. A portion of the energized part 122 and a portion of the negative electrode connection part 123 are located in the second reaction cell.

[0035] In this embodiment, the bipolar lithium-ion battery material evaluation chip arranges the positive electrode connection 121, the energized part 122, and the negative electrode connection 123 sequentially and spaced apart from each other. Combined with the first liquid flow channel 210 and the second liquid flow channel 220 in the upper cover 200, it forms two independent reaction pools. This enables the simultaneous construction of a micro-electrochemical reaction environment for both the positive and negative electrodes on the same chip, saving space, eliminating the need for additional wiring, and realistically simulating the migration process of lithium ions between the positive and negative electrodes. This allows for efficient and accurate evaluation of the electrochemical performance of the positive and negative electrode materials 300 during the charge and discharge process, thereby improving material screening efficiency.

[0036] like Figures 1 to 5 As shown, based on the above embodiment, the upper cover 200 is further provided with a first injection hole 230. One end of the first injection hole 230 is located on the side of the upper cover 200 away from the base 100, and the other end of the first injection hole 230 is connected to the first liquid flow channel 210.

[0037] In this embodiment, by providing a first injection hole 230 in the upper cover 200 that communicates with the first liquid flow channel 210, it is convenient to accurately inject electrolyte or replace test liquid into the first reaction cell from outside the chip, avoiding chip disassembly or damage to the sealing structure, improving experimental repeatability, and reducing the risk of liquid leakage.

[0038] like Figures 1 to 5 As shown, based on the above embodiment, the upper cover 200 is further provided with a second injection hole 240. One end of the second injection hole 240 is located on the side of the upper cover 200 away from the base 100, and the other end of the second injection hole 240 is connected to the second liquid flow channel 220.

[0039] In this embodiment, by providing a second injection hole 240 in the upper cover 200 that communicates with the second liquid flow channel 220, it is convenient to accurately inject electrolyte into the second reaction cell from outside the chip or replace the test liquid, avoiding chip disassembly or damage to the sealing structure, improving experimental repeatability, and reducing the risk of liquid leakage.

[0040] Furthermore, this design, in conjunction with the first injection port 230, enables independent liquid management of the first and second reaction cells, supports testing of differentiated electrolyte systems, and enhances the chip's applicability and flexibility.

[0041] like Figures 1 to 5As shown, based on the above embodiment, the energized part 122 is provided with a first load region 124 for loading the negative electrode material 300 at the position of the first reaction cell, and the energized part 122 is provided with a second load region 125 for loading the positive electrode material 400 at the position of the second reaction cell.

[0042] In this embodiment, a first load region 124 and a second load region 125 are respectively provided at the positions of the two reaction cells corresponding to the energized part 122, for directly loading the negative electrode material 300 and the positive electrode material 400. The negative electrode material 300 and the positive electrode material 400 are in close contact with the conductive layer 120, reducing the interface resistance, improving the electron conduction efficiency, and improving the test accuracy.

[0043] like Figures 1 to 5 As shown, based on the above embodiments, the insulating substrate 110 is made of ordinary glass, and the conductive layer 120 is set as a copper-plated indium tin oxide conductive layer 120.

[0044] Specifically, the indium tin oxide conductive layer can be deposited on the surface of ordinary glass at high temperature using magnetron sputtering technology. On this basis, the copper-plated indium tin oxide conductive layer can be composited by screen printing conductive copper paste, hot pressing copper foil, or bonding with conductive adhesive.

[0045] In this embodiment, ordinary glass is used as the insulating substrate 110, which is inexpensive, highly transparent, and easy to observe optically. The copper-plated indium tin oxide conductive layer 120 has both good conductivity and certain light transmittance, which not only meets the conductivity requirements of electrochemical testing, but also is compatible with optical detection methods such as microscopic observation and Raman spectroscopy, thus expanding the multi-functional integration potential of the chip.

[0046] like Figures 1 to 5 As shown, based on the above embodiments, the upper cover 200 is made of polydimethylsiloxane material.

[0047] In this embodiment, the top cover 200 is made of polydimethylsiloxane material, which has excellent flexibility, biocompatibility, chemical inertness and good sealing performance. It is easy to bond with the glass substrate 100 to form a stable microfluidic structure. Polydimethylsiloxane material is easy to microfabricate and is suitable for soft lithography process, which is conducive to the large-scale and low-cost manufacturing of chips.

[0048] like Figures 1 to 6 As shown, a method for evaluating the performance of lithium-ion battery positive and negative electrode materials 300 includes the following steps: S1. The mold is prepared using soft photolithography. The spatial contour of the mold is transferred to the upper cover 200 blank using an imprinting process, thereby forming a mold as shown in the image. Figure 2 The top cover 200 shown has a first liquid flow channel 210 and a second liquid flow channel 220 that are spaced apart from each other; Specifically, the top cover 200 is made of polydimethylsiloxane material.

[0049] S2. A conductive layer 120 is formed on the insulating substrate 110, such that the conductive layer 120 includes a positive electrode connection portion 121, a current-carrying portion 122, and a negative electrode connection portion 123 arranged sequentially and spaced apart from each other, thereby forming a structure as shown in the figure. Figure 1 The substrate 100 shown; The positive electrode connection portion 121, the energized portion 122, and the negative electrode connection portion 123 are arranged sequentially in the same direction and separated from each other, forming a shape similar to a straight line divided into three segments. They can all be disposed on the insulating substrate 110 in the same way.

[0050] Specifically, the insulating substrate 110 is made of ordinary glass, and the conductive layer 120 is a copper-plated indium tin oxide conductive layer 120.

[0051] More specifically, the indium tin oxide conductive layer can be deposited on the surface of ordinary glass at high temperature using magnetron sputtering technology. On this basis, the copper-plated indium tin oxide conductive layer can be composited by screen printing conductive copper paste, hot pressing copper foil, or bonding with conductive adhesive.

[0052] S3, such as Figure 3 As shown, the negative electrode material 300 is loaded in the first load region 124 of the first liquid flow channel 210 corresponding to the energized part 122, and the positive electrode material 400 is loaded in the second load region 125 of the second liquid flow channel 220 corresponding to the energized part 122. S4, such as Figure 4 As shown, the side of the substrate 100 with the conductive layer 120 is arranged opposite to the side of the top cover 200 with the liquid flow channel. The top cover 200 is connected to the substrate 100. After connection, the first liquid flow channel 210 and the substrate 100 enclose to form a first reaction cell, and the second liquid flow channel 220 and the substrate 100 enclose to form a second reaction cell. A part of the positive electrode connection 121 and a part of the energized part 122 are located inside the first reaction cell, and a part of the energized part 122 and another part of the negative electrode connection 123 are located inside the second reaction cell. S5. A first electrolyte is supplied to the first reaction tank and a second electrolyte is supplied to the second reaction tank, so that the interior of the first reaction tank is filled with the first electrolyte and the interior of the second reaction tank is filled with the second electrolyte. S6: As Figure 6 As shown, the positive electrode connection portion 121 and the negative electrode connection portion 123 of the substrate 100 are electrically connected to an electrochemical workstation or a lithium battery charging and discharging device, respectively. When a charging voltage excitation signal is applied, the positive electrode material 400 solid phase in the second reaction cell undergoes a delithiation oxidation reaction, and lithium ions leave the positive electrode solid phase and enter the second electrolyte. The lithium ions migrate directionally along the electrolyte to the first reaction cell and intercalate into the negative electrode material 300 solid phase, and the negative electrode material 300 solid phase undergoes a lithium intercalation reduction reaction. When a discharge voltage excitation signal is applied, the negative electrode material 300 solid phase in the first reaction cell undergoes a delithiation oxidation reaction, and lithium ions leave the negative electrode solid phase and enter the first electrolyte. The lithium ions migrate directionally along the electrolyte to the second reaction cell and intercalate into the positive electrode material 400 solid phase, where the positive electrode material 400 solid phase undergoes a lithium intercalation reduction reaction. The electrochemical workstation or lithium battery charging and discharging equipment is configured to output an excitation electrical signal to the conductive layer 120, and simultaneously collect and store the voltage, current, and impedance feedback electrical signals in the conductive circuit.

[0053] In this embodiment, the performance evaluation method for lithium-ion battery positive and negative electrode materials 300 constructs a well-structured and fully functional bipolar micro battery testing platform through a standardized microfabrication and assembly process. Its charging and discharging mechanism truly replicates the working principle of lithium-ion batteries and can simultaneously collect multi-dimensional electrochemical data such as voltage, current, and impedance, enabling dynamic, quantitative, and high-throughput evaluation of the performance of positive and negative electrode materials 300, significantly improving the efficiency of new material research and development.

[0054] like Figure 3 As shown, based on the above embodiment, in step S3, the negative electrode material 300 is loaded by applying the negative electrode slurry to the first load area 124 of the first liquid flow channel 210 corresponding to the energized part 122, and the positive electrode material 400 is loaded by applying the positive electrode slurry to the second load area 125 of the second liquid flow channel 220 corresponding to the energized part 122.

[0055] In this embodiment, a slurry coating method is used to load the positive electrode material 400 and the negative electrode material 300 in a designated load area. This method is simple to operate, requires less material, and has precise positioning. It is suitable for testing micro-samples. This method can be flexibly adapted to different types of electrode slurries, making it easy to quickly screen multiple material combinations and reduce R&D costs.

[0056] like Figure 4 As shown, based on the above embodiments, in step S4, plasma cleaning technology is used to bond the top cover 200 made of polydimethylsiloxane material to the ordinary glass substrate 100 provided with copper indium tin oxide conductive layer 120.

[0057] In this embodiment, plasma cleaning technology is used to achieve a strong bond between the top cover 200 made of polydimethylsiloxane material and the substrate 100 made of copper-plated indium tin oxide glass material. This not only improves the sealing performance and structural stability of the chip, but also avoids pollution or electrochemical interference caused by adhesives, ensuring a clean testing environment and improving data reliability.

[0058] like Figure 5 As shown, based on the above embodiment, in step S5, before supplying the first electrolyte to the first reaction cell and the second electrolyte to the second reaction cell, a first injection hole 230 is made from the side of the upper cover 200 away from the substrate 100 and connected to the first liquid flow channel 210, and a second injection hole 240 is made from the side of the upper cover 200 away from the substrate 100 and connected to the second liquid flow channel 220. The first electrolyte is supplied to the first reaction cell through the first injection hole 230, and the second electrolyte is supplied to the second reaction cell through the second injection hole 240.

[0059] In this embodiment, an injection hole is drilled and connected to the corresponding flow channel before injecting the electrolyte, so that the liquid injection path is clear and the operation is controllable, avoiding residual bubbles or cross-contamination of liquids. This step is compatible with the overall chip manufacturing process, ensuring that the first reaction cell and the second reaction cell are filled independently and do not interfere with each other, providing a guarantee for precise control of electrolyte composition and volume, and further improving the repeatability and accuracy of test results.

[0060] The following description is based on several specific embodiments: Example 1: Charge and Discharge The negative electrode material 300 (artificial graphite) and the positive electrode material 400 (lithium iron phosphate) were respectively loaded onto the first loading region 124 and the second loading region 125 at both ends of the energized section 122. Ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate were mixed in a volume ratio of 1:1:1, and 1 mol / L LiPF6 was added to prepare electrolyte A. Electrolyte A was added to both the first liquid flow channel 210 and the second liquid flow channel 220. Constant current charging was performed under conditions of 3.85V-5.6V voltage and a charging rate of 0.33C to obtain the desired result. Figure 7 The charging curve shown illustrates that as the state of charge (SOC) increases, the battery voltage rises and exhibits a significant plateau voltage, demonstrating behavior similar to that of a typical battery. Constant current discharge was performed at a discharge rate of 0.33C and a voltage range of 2.3V-1.55V, yielding the following results: Figure 8 The charging curve shows that as the discharge SOC increases, the battery voltage decreases and there is a significant plateau voltage, exhibiting behavior similar to that of a normal battery.

[0061] The above demonstrates that bipolar batteries exhibit similar rechargeability and charge / discharge curve characteristics to ordinary batteries.

[0062] Example 2: Discharge performance of different materials Different graphite anode materials 300, such as material a (a secondary particle carbonized material) and ordinary single particle uncarbonized material b, were loaded into the first load region 124 of the energized section 122. The same lithium iron phosphate was used as the cathode material 400. Constant current discharge tests were performed on the materials. At a rate of 0.33C, the bipolar electrode voltage was discharged to 1.55V, resulting in... Figure 9 The discharge curves shown indicate that as the discharge progresses, the cell voltage decreases to a plateau voltage and then drops rapidly. Different materials exhibit different plateau voltages and different degrees of polarization at the same discharge rate.

[0063] Discharge performance can be judged by factors such as plateau voltage, using methods similar to those used for evaluating ordinary lithium-ion batteries.

[0064] Example 3: Rate Performance Test Material a of the secondary particulate carbon was loaded onto the first load region 124 of the energized section 122, with the other end being a lithium iron phosphate terminal. Constant current discharge tests were performed on the material at 0.2C, 0.33C, and 1C. Using 0.33C as the capacity reference, the measured capacity ratio was 1.05:1:0.74.

[0065] Example 4: Different electrolytes at the two electrodes of the energized part 122 Ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate were mixed in a volume ratio of 1:1:1, and 1 mol / L LiPF6 was added. Based on the solvent, 0.5% by mass of fluoroethylene carbonate, 2% by mass of vinylene carbonate, and 0.5% by mass of the mixture were added to prepare electrolyte B.

[0066] Experimental Group 1: Electrolyte A was added to the first liquid flow channel 210, and electrolyte A was added to the second liquid flow channel 220. Experimental Group 2: Electrolyte A was added to the first liquid flow channel 210, and electrolyte B was added to the second liquid flow channel 220. Experimental Group 3: Electrolyte B was added to the first liquid flow channel 210, and electrolyte A was added to the second liquid flow channel 220.

[0067] Comparing their 0.33C discharge performance, their capacity ratio is 1:1.04:1.01:1.05, indicating that the positive and negative electrodes of lithium-ion batteries have different sensitivities to the electrolyte.

[0068] Example 5: Parallel driving of the 122-electrified array The negative electrode material 300 is artificial graphite and the positive electrode material 400 is lithium iron phosphate, respectively loaded onto a chip array. Figure 1The first load area 124 and the second load area 125 of the three energized sections 122 shown are capable of simultaneous constant current charging of three channels at a voltage of 3.85V-5.6V.

Claims

1. A bipolar lithium-ion battery material evaluation chip, characterized in that, include: The substrate includes an insulating substrate and a conductive layer. The conductive layer is disposed on the insulating substrate and includes a positive electrode connection portion, a current-carrying portion and a negative electrode connection portion. The positive electrode connection portion, the current-carrying portion and the negative electrode connection portion are arranged sequentially and spaced apart from each other. The top cover is provided with a first liquid flow channel and a second liquid flow channel, both of which are tank structures and are separated from each other; The substrate is connected to the top cover, the conductive layer is located on the side of the substrate near the top cover, and the first liquid channel and the second liquid channel are located on the side of the top cover near the substrate; A first reaction cell is formed between the first liquid channel and the substrate. The first reaction cell is used to contain the first electrolyte and the negative electrode material. A portion of the positive electrode connection and a portion of the energized portion are both located in the first reaction cell. A second reaction cell is formed between the second liquid channel and the substrate. The second reaction cell is used to contain the second electrolyte and the positive electrode material. A portion of the energized part and a portion of the negative electrode connection part are located in the second reaction cell.

2. The bipolar lithium-ion battery material evaluation chip according to claim 1, characterized in that, The top cover is also provided with a first injection hole, one end of which is located on the side of the top cover away from the base, and the other end of which is connected to the first liquid flow channel.

3. The bipolar lithium-ion battery material evaluation chip according to claim 1, characterized in that, The top cover is also provided with a second injection hole, one end of which is located on the side of the top cover away from the base, and the other end of which is connected to the second liquid flow channel.

4. The bipolar lithium-ion battery material evaluation chip according to claim 1, characterized in that, The energized part is provided with a first load area for loading negative electrode material at the position of the first reaction cell, and the energized part is provided with a second load area for loading positive electrode material at the position of the second reaction cell.

5. The bipolar lithium-ion battery material evaluation chip according to claim 1, characterized in that, The insulating substrate is made of ordinary glass, and the conductive layer is a copper-plated indium tin oxide conductive layer.

6. The bipolar lithium-ion battery material evaluation chip according to claim 1, characterized in that, The top cover is made of polydimethylsiloxane material.

7. A method for evaluating the performance of positive and negative electrode materials for lithium-ion batteries, characterized in that, Including the following steps: S1. The mold is prepared by soft photolithography and the spatial contour of the mold is transferred to the upper cover blank by imprinting process, thereby forming an upper cover with a first liquid flow channel and a second liquid flow channel that are separated from each other. S2. A conductive layer is provided on an insulating substrate, such that the conductive layer includes a positive electrode connection portion, a current-carrying portion and a negative electrode connection portion arranged sequentially and spaced apart from each other, thereby forming a substrate; S3. Load a negative electrode material in the first load area corresponding to the first liquid flow channel in the energized part, and load a positive electrode material in the second load area corresponding to the second liquid flow channel in the energized part. S4. Arrange the side of the substrate with the conductive layer opposite to the side of the top cover with the liquid flow channel. Connect the top cover to the substrate. After connection, the first liquid flow channel and the substrate enclose to form a first reaction cell. The second liquid flow channel and the substrate enclose to form a second reaction cell. A part of the positive electrode connection part and a part of the energized part are located inside the first reaction cell. The other part of the energized part and a part of the negative electrode connection part are located inside the second reaction cell. S5. A first electrolyte is supplied to the first reaction tank and a second electrolyte is supplied to the second reaction tank, so that the interior of the first reaction tank is filled with the first electrolyte and the interior of the second reaction tank is filled with the second electrolyte. S6: Electrically connect the positive electrode connection and negative electrode connection of the substrate to an electrochemical workstation or lithium battery charging and discharging equipment respectively; When a charging voltage excitation signal is applied, the solid phase of the positive electrode material in the second reaction cell undergoes a delithiation oxidation reaction, and lithium ions leave the solid phase of the positive electrode and enter the second electrolyte. The lithium ions migrate directionally along the electrolyte to the first reaction cell and are embedded in the solid phase of the negative electrode material, and the solid phase of the negative electrode material undergoes a lithium intercalation reduction reaction. When a discharge voltage excitation signal is applied, the solid phase of the negative electrode material in the first reaction cell undergoes a delithiation oxidation reaction, and lithium ions leave the solid phase of the negative electrode and enter the first electrolyte. The lithium ions migrate directionally along the electrolyte to the second reaction cell and intercalate into the solid phase of the positive electrode material, where the solid phase of the positive electrode material undergoes a lithium intercalation reduction reaction. Among them, the electrochemical workstation or lithium battery charging and discharging equipment is configured to output excitation electrical signals to the conductive layer, and simultaneously collect and store the voltage, current and impedance feedback electrical signals in the conductive circuit.

8. The method for evaluating the performance of positive and negative electrode materials of lithium-ion batteries according to claim 7, characterized in that, In step S3, the loading of the negative electrode material is achieved by applying the negative electrode slurry to the first load area corresponding to the first liquid flow channel of the energized part, and the loading of the positive electrode material is achieved by applying the positive electrode slurry to the second load area corresponding to the second liquid flow channel of the energized part.

9. The method for evaluating the performance of positive and negative electrode materials of lithium-ion batteries according to claim 7, characterized in that, In step S4, plasma cleaning technology is used to bond the top cover made of polydimethylsiloxane material to the substrate made of ordinary glass material with a copper indium tin oxide conductive layer.

10. The method for evaluating the performance of positive and negative electrode materials of lithium-ion batteries according to claim 7, characterized in that, In step S5, before supplying the first electrolyte to the first reaction cell and the second electrolyte to the second reaction cell, a first injection hole is made on the side of the top cover away from the substrate and connected to the first liquid flow channel, and a second injection hole is made on the side of the top cover away from the substrate and connected to the second liquid flow channel. The first electrolyte is supplied to the first reaction cell through the first injection hole, and the second electrolyte is supplied to the second reaction cell through the second injection hole.

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