Electrode material microscopic interface performance test platform and application thereof
By using the microinterface performance test platform of electrode materials in lithium-ion batteries, the microinterface between carbon nanotubes and silicon-based negative electrodes is analyzed, and the volume expansion and SEI instability of conductive agents in lithium-ion batteries is solved, and the application of lithium-ion batteries is provided. New ideas.
Patent Information
- Application Number
- CN202411379527.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-01-07
AI Technical Summary
As a conductive agent, carbon nanotubes in existing lithium-ion batteries have problems such as large volume expansion and SEI instability. It is necessary to explore the impact of different types of carbon tubes on the ion diffusion and cycling performance of silicon-based anode from the microscopic level.
Provide a micro-interface performance test platform for electrode materials. It builds a test platform through single carbon nanotubes and single particles to analyze the dynamic structural changes and micromechanical mechanisms of complex electrochemical interfaces at the micro level, combine it with the sealed cavity to provide an inert gas environment, and use the exploration Needle manipulation and assembled single-particle microcells for charge and discharge testing and Raman spectral acquisition to achieve in-situ characterization.
Non-destructive detection of the interface between conductive agent and silicon-based negative electrode active material is achieved, material stress analysis and stability strategies are provided, and the relationship between microscopic performance and macroscopic electrochemical performance is established, providing a new idea for the application of lithium batteries.
Smart Images
Figure CN119269598A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electrode material performance testing, and in particular to an electrode material microscopic interface performance testing platform and application thereof. Background Art
[0002] In the transition from fossil fuels to sustainable energy, batteries play an indispensable role due to their efficient storage and release characteristics. At present, rechargeable lithium-ion batteries (LIBs) are the leading technology in the information industry, involving consumer electronics, environmentally friendly power grids, aerospace, and electric vehicles. Silicon-based anode materials (alloy-type anodes) are ideal anode materials for next-generation lithium-ion batteries due to their high energy density. In practical applications, in order to improve the conductivity of anode materials, a small amount of conductive carbon is added to silicon-based anodes as a conductive network. Carbon nanotubes are the most commonly used type of conductive agent. They have excellent conductivity and mechanical properties brought by the intrinsic sp2 covalent structure, good chemical stability, and have broad application prospects in energy storage fields such as lithium-ion batteries. Carbon nanotubes are considered to be the most ideal conductive additives for silicon-based anodes, with the following advantages: providing electron transmission pathways, which are conducive to electrochemical reactions; forming a flexible network structure to buffer the huge volume changes of the electrode during the reaction; providing a mechanical skeleton, which helps the dispersion of active substances and accelerates ion transport. The one-dimensional tubular structure can serve as a supporting skeleton in the electrode and can also construct an excellent long-range conductive network. Carbon nanotubes as a conductive agent can greatly improve its performance.
[0003] However, lithium-ion batteries using carbon nanotubes as conductive agents still have problems such as large volume expansion and unstable SEI. Therefore, it is necessary to explore the effects of different types of carbon nanotubes on the ion diffusion and circulation performance of silicon-based negative electrodes from a microscopic level. Summary of the invention
[0004] In view of the above-mentioned problems existing in the prior art, the present invention provides a testing platform for the microscopic interface performance of electrode materials and its application. The present invention uses a single carbon nanotube and a single particle to build a testing platform, which provides support for the subsequent analysis of the dynamic structural changes of complex electrochemical interfaces at the microscopic level, and the analysis of micromechanical mechanisms, including force analysis and stability strategies of materials, and establishes its relationship with macroscopic electrochemical properties, providing a new idea for the future application of silicon-based negative electrodes for lithium batteries in terms of basic understanding, method strategies and macroscopic applications.
[0005] The specific content of the invention is as follows:
[0006] In a first aspect, the present invention provides an electrode material micro-interface performance testing platform, comprising a single-particle micro-battery and a sealed cavity; wherein:
[0007] The single-particle microbattery is composed of a single-particle microelectrode, a lithium source, an electrolyte and a current collector;
[0008] The single-particle microelectrode is composed of a carbon nanotube and a single active particle structure combined with each other;
[0009] The carbon nanotube is a single carbon nanotube or a carbon nanotube bundle consisting of a single carbon nanotube;
[0010] The single particle structure is composed of a silicon-based active substance;
[0011] The sealed cavity is used to provide an inert gas testing environment for the testing platform.
[0012] Optionally, the single carbon nanotube includes a single-walled carbon nanotube, a double-walled carbon nanotube or a multi-walled carbon nanotube, and has a diameter greater than 1 nm.
[0013] Optionally, the diameter of the carbon nanotube bundle is 1 nm-1000 mm.
[0014] Optionally, the electrolyte is combined with the single active particle structure in the form of interfacial contact;
[0015] The electrolyte is combined with the lithium source in interfacial contact.
[0016] Optionally, the electrolyte is a solid electrolyte.
[0017] Optionally, the lithium source is a lithium sheet or a lithium alloy.
[0018] Optionally, the current collector consists of a first probe and a second probe, wherein the first probe is used to electrify the single active particle structure, and the second probe is used to electrify the carbon nanotube.
[0019] Optionally, the single carbon nanotube is grown in mid-air between two cross-seam silicon wafers.
[0020] Optionally, the carbon nanotubes and a single active particle structure are combined with each other, including: the suspended carbon nanotubes are wrapped on the surface of the single active particle structure; or
[0021] The single active particle structure is tightly combined with the suspended carbon nanotubes through van der Waals forces.
[0022] In a second aspect, the present invention provides an application of the electrode material microscopic interface performance testing platform described in the first aspect, the application comprising:
[0023] S1. Using probe manipulation, wrap carbon nanotubes on the surface of a single active particle structure, or transfer a single active particle structure to the carbon nanotubes, and use van der Waals force to tightly combine the two to obtain a single particle microelectrode;
[0024] S2. In an inert gas test environment, the lithium source and the electrolyte are combined in the form of interface contact by using probe manipulation, and the lithium source and the electrolyte are fixed at the tip of the first probe, and then the first probe fixed with the lithium source and the electrolyte is contacted with a single active particle structure constituting the single particle microelectrode; the second probe is used to power the carbon nanotubes to complete the assembly of the microbattery;
[0025] S3, powering the first probe and the second probe to perform charge and discharge tests, while collecting the Raman spectrum of the carbon nanotubes to achieve in-situ characterization of the single-particle contact state, the mechanical properties of the carbon nanotubes, and the performance of the single-particle battery.
[0026] Compared with the prior art, the present invention has the following advantages:
[0027] The present invention provides a micro-interface performance testing platform for electrode materials, including a single-particle micro-battery and a sealed cavity; wherein the single-particle micro-battery is composed of a single-particle micro-electrode, a lithium source, an electrolyte and a current collector; the single-particle micro-electrode is composed of a carbon nanotube and a single active particle structure combined with each other; the carbon nanotube is a single carbon nanotube grown in mid-air, or a carbon nanotube bundle composed of a single carbon nanotube; the single particle structure is composed of a silicon-based active substance; and the sealed cavity is used to provide an inert gas testing environment for the testing platform. The present invention uses a microelectrode to measure the local information of the reaction interface, including in-situ characterization and non-destructive detection of electrical, mechanical and other signals; the present invention uses carbon nanotubes and single particles to build a testing platform, which provides support for subsequent analysis of dynamic structural changes of complex electrochemical interfaces at the microscopic level, analysis of micromechanical mechanisms, including force analysis and stability strategies of materials, and establishes its relationship with macroscopic electrochemical performance, providing a new idea for the application of silicon-based negative electrodes of lithium batteries in the future from the perspectives of basic understanding, method strategies and macroscopic applications.
[0028] The electrode material micro-interface performance testing platform provided by the present invention is used for non-destructive detection of electrical, mechanical and other signals between a conductive agent and a silicon-based negative electrode active material at a microscopic interface. The carbon nanotube is wrapped on the surface of a single active particle structure by probe manipulation, or the single active particle structure is transferred to a suspended carbon nanotube, and the two are tightly combined by van der Waals force to obtain a single-particle micro-electrode; in an inert gas test environment, the lithium source and the electrolyte are combined in the form of interface contact by probe manipulation, and the lithium source and the electrolyte are then fixed at the needle tip of the first probe, and then the first probe fixed with the lithium source and the electrolyte is contacted with the single active particle structure constituting the single-particle micro-electrode to power the carbon nanotube and complete the assembly of the micro-battery; the first probe and the second probe are powered, and a charge and discharge test is performed, and the Raman spectrum of the carbon nanotube is collected at the same time, so that the single-particle contact state and the mechanical properties of the carbon nanotube and the single-particle battery performance can be characterized in situ. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0030] Figure 1 A schematic diagram of the structure of a single-particle microbattery provided in an embodiment of the present invention is shown;
[0031] Figure 2 The application flow chart of the electrode material micro-interface performance testing platform provided by the embodiment of the present invention is shown;
[0032] Figure 3 An optical microscope image of the structure of a single active particle of SiOx@C provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION
[0033] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.
[0034] In the embodiment, no specific experimental steps or conditions are indicated, and the operation or conditions of the conventional experimental steps described in the prior art in this field can be carried out. The reagents used and other instruments that do not indicate the manufacturer are conventional reagent products that can be obtained commercially. In addition, the accompanying drawings are only schematic diagrams of the embodiments of the present invention and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted. Some block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities.
[0035] In a first aspect, the present invention provides a platform for testing the microscopic interface properties of electrode materials, including a single-particle microbattery and a sealed cavity acting on the outside of the single-particle microbattery; Figure 1 FIG. 4 shows a schematic diagram of the structure of a single-particle microbattery provided in an embodiment of the present invention. Figure 1 As shown, the single-particle microbattery is composed of a single-particle microelectrode, a lithium source 4, an electrolyte 5 and a current collector; the single-particle microelectrode is composed of a carbon nanotube 7 and a single active particle structure 6 combined with each other; the carbon nanotube 7 can be a single carbon nanotube grown in midair, specifically a single-walled carbon nanotube, a double-walled carbon nanotube or a multi-walled carbon nanotube; its diameter is nanometer-scale, greater than 1nm; or it can be a bundle composed of a single carbon nanotube, and the bundle diameter is 1nm-1000mm; as an example, the carbon nanotube 7 can be a single carbon nanotube grown in midair between two cross-seam silicon wafers 3, or it can be a bundle structure composed of multiple single carbon nanotubes; the carbon nanotube 7 and the single active particle structure 6 are combined with each other to obtain a single-particle microelectrode, and the combination of the two can be that the carbon nanotube 7 is wrapped on the surface of the single active particle structure 6; or the single active particle structure 6 is tightly combined with the carbon nanotube 7 through van der Waals force. The single particle structure 6 is composed of silicon-based active substances. The sealed cavity is used to isolate the single-particle microbattery from the outside world to ensure an internal inert gas environment during testing. The sealed cavity is provided with an outward air extraction port and an inward air inlet to facilitate adjustment of the environmental requirements for assembly and testing of the test platform.
[0036] Among the components constituting the single-particle microbattery, the lithium source 4 acts as a counter electrode, the electrolyte 5 is an ion conductor, and the current collector is used to collect and transmit current, and is electrically combined with the single-particle microelectrode to form a single-particle microbattery. As one of the combining modes, the electrolyte can be combined with a single active particle structure in the form of interface contact; at the same time, the electrolyte is also combined with the lithium source in the form of interface contact.
[0037] It should be noted that the electrolyte applicable to the present invention is a solid electrolyte. The lithium source is a lithium sheet or a lithium alloy; the current collector can be composed of a first probe 1 and a second probe 2; wherein the first probe 1 is used to power a single active particle structure, and the second probe 2 is used to power the carbon nanotube 7 and complete the task of collecting and transmitting current.
[0038] The electrode material micro-interface performance testing platform provided by the present invention uses suspended carbon nanotubes and single active particle structures as components of a microelectrode, and the microelectrode is used to build a testing platform, thereby achieving accurate in-situ characterization of the contact state of a single active particle and the electrical and mechanical properties of the carbon nanotube, and providing research data for non-destructive detection of electrical, mechanical and other signals of the micro-interface inside a lithium-ion battery.
[0039] In a second aspect, the present invention provides an application of the electrode material microscopic interface performance testing platform described in the first aspect, the application comprising:
[0040] S1. Using probe manipulation, wrap carbon nanotubes on the surface of a single active particle structure, or transfer a single active particle structure to the carbon nanotubes, and use van der Waals force to tightly combine the two to obtain a single particle microelectrode;
[0041] S2. In an inert gas test environment, the lithium source and the electrolyte are combined in the form of interface contact by using probe manipulation, and the lithium source and the electrolyte are fixed at the tip of the first probe, and then the first probe fixed with the lithium source and the electrolyte is brought into contact with the single active particle structure constituting the single particle microelectrode; the second probe is used to power the carbon nanotubes to complete the assembly of the microbattery;
[0042] S3, powering the first probe and the second probe to perform charge and discharge tests, while collecting the Raman spectrum of the carbon nanotubes to achieve in-situ characterization of the single-particle contact state, the mechanical properties of the carbon nanotubes, and the performance of the single-particle battery.
[0043] In order to enable those skilled in the art to more clearly understand the present invention, an electrode material microscopic interface performance testing platform and its application described in the present invention are now described in detail through the following examples.
[0044] The following embodiments all adopt Figure 1 The structural schematic diagram shows the assembly of a single-particle microbattery, and on this basis, a sealed cavity is added ( Figure 1 The test platform is constructed by the following steps (not shown in the figure), and the entire construction process is performed in an inert gas atmosphere.
[0045] Example 1
[0046] (1) Using probe manipulation, the SiOx@C single active particle structure is transferred to the suspended double-walled carbon nanotube. The van der Waals force makes the two tightly bonded to obtain a microelectrode. The optical microscope image of the SiOx@C single active particle structure is shown in Figure 2. Figure 3 shown.
[0047] (2) Evacuate the sealed chamber and introduce inert gas.
[0048] (3) Using probe manipulation, the lithium source 4 and the electrolyte 5 are combined in the form of interface contact and then fixed on the first probe (the first probe is in interface contact with the lithium source 4), and then the first probe is contacted with the single active particle structure of the microelectrode, and the second probe is contacted with the double-walled carbon nanotubes to complete the preparation of the microbattery.
[0049] (4) Powering the first probe and the second probe to perform charge and discharge tests, while collecting the Raman spectrum of the carbon nanotubes to achieve in-situ characterization of the single particle contact state and carbon nanotube mechanics.
[0050] Example 2
[0051] (1) Using probe manipulation, the single active particle structure of SiO@C is transferred to the suspended double-walled carbon nanotubes, and the van der Waals force makes the two tightly combined to obtain a microelectrode.
[0052] (2) Evacuate the sealed chamber and introduce inert gas.
[0053] (3) Using probe manipulation, the lithium source 4 and the electrolyte 5 are combined in the form of interface contact and then fixed on the first probe (the first probe is in interface contact with the lithium source 4), the first probe is contacted with the single active particle structure of the microelectrode, and the second probe is contacted with the double-walled carbon nanotube, thereby completing the preparation of the microbattery.
[0054] (4) Powering the first probe and the second probe to perform charge and discharge tests, while collecting the Raman spectrum of the carbon nanotubes to achieve in-situ characterization of the single particle contact state and carbon nanotube mechanics.
[0055] Example 3
[0056] (1) Using probe manipulation, a single carbon nanotube is wrapped around the Si@C single active particle structure and bound to the tip of the second probe.
[0057] (2) Evacuate the sealed chamber and introduce inert gas.
[0058] (3) Using probe manipulation, the lithium source 4 and the electrolyte 5 are combined in the form of interface contact, and then fixed at the tip of the first probe (the tip of the first probe is in interface contact with the lithium source 4), and the first probe is brought into contact with the second probe to complete the preparation of the microbattery.
[0059] (4) The first probe and the second probe are powered to perform charge and discharge tests, and the Raman spectrum of the carbon nanotubes is collected at the same time to achieve in-situ characterization of the single particle contact state and carbon nanotube mechanics.
[0060] The test platform assembled in Example 1 was used to investigate the changes in the mechanics and contact state of the carbon tube during the charge and discharge of the micro-battery. The test results are shown in Table 1:
[0061] Table 1 Changes in the mechanics and contact state of carbon tubes during charge and discharge of micro batteries
[0062] Voltage Before power on 1.5V 1.2V 0.9V 0.6V 0.3V 0.01V Stress(GPa) 0 0.1 0.3 0.7 0.9 -3.8 0.1 Contact status good good good good good Disengagement good
[0063] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.
[0064] For the method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the order of the actions described, because according to the present invention, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and components involved are not necessarily required by the present invention.
[0065] The above is a detailed introduction to an electrode material micro-interface performance testing platform and its application provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technicians in this field, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.
Claims
1. A microscopic interface performance testing platform for electrode materials, characterized in that: It includes a single-particle micro battery and a sealed cavity; wherein, The single-particle microbattery is composed of a single-particle microelectrode, a lithium source, an electrolyte and a current collector; The single-particle microelectrode is composed of a carbon nanotube and a single active particle structure combined with each other; The carbon nanotube is a single carbon nanotube or a carbon nanotube bundle consisting of a single carbon nanotube; The single particle structure is composed of a silicon-based active substance; The sealed cavity is used to provide an inert gas testing environment for the testing platform.
2. The test platform according to claim 1, characterized in that: The single carbon nanotube includes a single-walled carbon nanotube, a double-walled carbon nanotube or a multi-walled carbon nanotube, and has a diameter greater than 1 nm.
3. The test platform according to claim 1, characterized in that: The diameter of the carbon nanotube bundle is 1nm-1000mm.
4. The test platform according to claim 1, characterized in that: The single carbon nanotube is grown in mid-air between two cross-seam silicon wafers.
5. The test platform according to claim 1, characterized in that: The electrolyte is combined with the single active particle structure in the form of interfacial contact; The electrolyte is combined with the lithium source in interfacial contact.
6. The test platform according to claim 1, characterized in that: The electrolyte is a solid electrolyte.
7. The test platform according to claim 1, characterized in that: The lithium source is a lithium sheet or a lithium alloy.
8. The test platform according to claim 1, characterized in that: The current collector consists of a first probe and a second probe, wherein the first probe is used to electrify the single active particle structure, and the second probe is used to electrify the carbon nanotube.
9. The test platform according to claim 1, characterized in that: The carbon nanotubes and the single active particle structure are combined with each other, including: the carbon nanotubes are wrapped on the surface of the single active particle structure; or The single active particle structure is tightly combined with the carbon nanotubes through van der Waals forces.
10. An application of the electrode material micro-interface performance testing platform according to any one of claims 1 to 9, characterized in that: The applications include: S1. Using probe manipulation, wrap carbon nanotubes on the surface of a single active particle structure, or transfer a single active particle structure to the carbon nanotubes, and use van der Waals force to tightly combine the two to obtain a single particle microelectrode; S2. In an inert gas test environment, the lithium source and the electrolyte are combined in the form of interface contact by using probe manipulation, and the lithium source and the electrolyte are fixed at the tip of the first probe, and then the first probe fixed with the lithium source and the electrolyte is contacted with a single active particle structure constituting the single particle microelectrode; the second probe is used to power the carbon nanotubes to complete the assembly of the microbattery; S3, powering the first probe and the second probe to perform charge and discharge tests, while collecting the Raman spectrum of the carbon nanotubes to achieve in-situ characterization of the single-particle contact state, mechanical properties of the carbon nanotubes, and single-particle battery performance.