An electronic timing control method for inhibiting lithium dendrites of lithium batteries

Abstract

The application discloses an electronic timing control method for inhibiting lithium dendrites of a lithium battery, and belongs to the technical field of lithium ion batteries. The application is aimed at the bottom nature of lithium dendrite generation, that is, the transmission timing difference between electrons and lithium ions. Through the one-way rectification characteristics of a Schottky functional unit, the transmission timing of negative electrode electrons is accurately controlled. During charging, the reverse cutoff characteristics are used to block the early enrichment of electrons. After the embedding of lithium ions is completed, the electrons are allowed to be synchronously turned on, so that the condition for generating lithium dendrites is eliminated from the root. During discharging, the forward conduction characteristics are used to ensure that the electrons can flow back without any obstruction, and the performance of the battery is not sacrificed. The application is a bottom general control method, which is suitable for the whole system and all scenes, is not limited by specific materials, structures and processes, can completely eradicate the lithium dendrite pain point, greatly improves the cycle life and safety of the lithium battery, and has extremely strong commercial value.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to a control method that regulates electron transport behavior through unidirectional rectification characteristics to eliminate the conditions for lithium dendrite formation at the source, and can be adapted to all types of lithium-ion battery systems. Background Technology

[0002] Lithium-ion batteries, with their core advantages such as high energy density, long cycle life, and no memory effect, have become the mainstream electrochemical energy storage devices in new energy vehicles, energy storage power stations, and consumer electronics. However, since their commercialization, the growth of lithium dendrites has always been a core industry pain point restricting the safety, cycle life, and fast-charging performance of lithium batteries. Especially in fast-charging, low-temperature, and high-rate cycling scenarios, the continuous growth of lithium dendrites can easily puncture the separator, causing serious safety accidents such as internal short circuits, thermal runaway, and even fires and explosions.

[0003] In existing technologies, solutions for suppressing lithium dendrites mainly fall into three categories, all of which suffer from insurmountable underlying defects: 1. Modification of negative electrode active materials: Improving the lithium-ion intercalation environment through graphite particle size optimization, silicon-carbon composite modification, surface coating, etc. can only alleviate the dendrite growth rate, but does not address the core root cause of lithium dendrite formation, and cannot fundamentally eliminate dendrite formation. 2. Electrolyte system optimization: A SEI film is formed on the surface of the negative electrode by film-forming additives to inhibit dendrite growth. However, the SEI film will age, break, and regenerate continuously with charge and discharge cycles, resulting in a limited cycle life. It will also significantly increase the internal resistance of the battery, sacrificing the rate performance and energy density of the battery. 3. Solid electrolyte alternatives: Inorganic or polymer solid electrolytes are used to block dendrite penetration, but they have problems such as high interfacial contact resistance, extremely high production costs, difficulty in mass production, and low compatibility with existing production lines, which prevents large-scale commercialization.

[0004] None of the above solutions have completely resolved the fundamental contradiction in the formation of lithium dendrites: during the charging process, the transport speed of electrons is at the speed of light, while the migration speed of lithium ions is at the speed of minutes, resulting in a huge natural time difference between the two; electrons will accumulate on the surface of the negative electrode active material in advance, and directly pair with the lithium ions that have just migrated to the surface to reduce them into metallic lithium, which will eventually continue to grow into lithium dendrites.

[0005] To date, there is no universal technical solution globally that can regulate electron transport timing through unidirectional rectification characteristics, fundamentally match the transport rhythm of electrons and lithium ions, and completely eliminate the conditions for lithium dendrite formation. Furthermore, there is no related mature technology that has been commercialized. This solution fills the core technological gap in this field. Summary of the Invention

[0006] I. Technical problems to be solved This invention addresses the fundamental shortcomings of existing technologies and aims to achieve the following core objectives: 4. Breaking through the limitations of existing technologies that can only alleviate dendrite formation but not eradicate it, this paper proposes a control method that can completely eliminate the conditions for lithium dendrite formation from the root, based on the essential principle of lithium dendrite formation. 5. Solve the industry pain point that existing dendrite suppression solutions often sacrifice battery performance, completely suppressing dendrites without affecting the battery's rate performance, power output, and energy density. 6. Provides a control method that is universally applicable to all scenarios and systems, and is not limited by battery form, positive and negative electrode material system, or production process, and can be adapted to all types of lithium-ion batteries; 7. Breaking away from the dependence of existing solutions on specific preparation processes and material structures, this method provides a low-level, universal control logic that can be implemented by those skilled in the art through various conventional technical means without requiring creative effort.

[0007] II. Core Technology Solution The core technical solution of this invention is to precisely control the electron transport timing of the lithium battery negative electrode by utilizing the intrinsic unidirectional rectification characteristics of the Schottky structure, thereby completely matching the transport rhythm of electrons and lithium ions and eliminating the conditions for lithium dendrite formation from the root. Specifically, it includes the following steps: 8. Functional unit layout: In the electron transport path of the negative electrode of the lithium battery, a Schottky functional unit with unidirectional rectification characteristics is set. The Schottky functional unit has intrinsic rectification characteristics of reverse cutoff and forward conduction. 9. Charging timing control: During charging, the reverse cutoff characteristic of the Schottky functional unit is used to block the premature transport of electrons to the negative electrode active surface, fundamentally preventing the premature accumulation of electrons on the negative electrode active surface; after lithium ions migrate to the negative electrode active site through the electrolyte and complete the insertion, the forward conduction characteristic of the Schottky functional unit allows electrons to pass through the Schottky functional unit synchronously and pair with the lithium ions that have been inserted into the active site, strictly achieving the timing matching of "ion leader, electron lag", completely eliminating the time difference between electron and lithium ion transport, and eliminating the conditions for lithium dendrite formation from the root; 10. Discharge conduction control: During the discharge process, the positive low resistance conduction characteristics of the Schottky functional unit are utilized to ensure that the electrons flow back from the negative electrode active material to the current collector without any obstruction. This does not affect the battery's discharge rate and power output, achieving the core effect of "controllable charging and smooth discharge". Beneficial effects

[0008] 11. Completely eliminate lithium dendrites at the source: This invention breaks through the limitations of the existing technology of "passively blocking dendrites". Starting from the essential principle of lithium dendrite formation, it completely eliminates the time difference between electron and lithium ion transmission through electronic timing control, thereby eliminating the conditions for lithium dendrite formation at the source and achieving a fundamental technological breakthrough from "alleviating dendrites" to "eradicating dendrites". 12. Zero-sacrifice battery core performance: This invention achieves electronic controllability during charging and smooth electronic flow during discharging through the intrinsic unidirectional rectification characteristics of the Schottky structure, without increasing the battery's internal resistance or sacrificing its rate performance, power output, and energy density. This solves the industry pain point of "performance degradation upon dendrite suppression" in existing solutions. 13. Universality across all systems and scenarios: This invention is a universal control method at the underlying level, which is not limited by battery form (pouch, cylindrical, square, blade battery), positive and negative electrode material system (positive electrode such as lithium iron phosphate, ternary lithium, lithium manganese oxide, etc., negative electrode such as graphite, silicon carbon, hard carbon, etc.), or production process. It can be adapted to all types of lithium-ion batteries and has a very wide range of applications. 14. Strong feasibility: This invention only limits the core control logic and does not limit the specific implementation method. Those skilled in the art can implement this method through a variety of conventional technical means in the semiconductor and lithium battery fields. No special equipment or modification of existing production lines is required, which has strong commercialization value. 15. Ultra-long cycle stability: This invention eliminates lithium dendrite formation at the source, avoiding problems such as repeated SEI film rupture and regeneration, active material loss, and internal short circuits caused by dendrite growth. It can increase the cycle life of lithium batteries by more than 100% and significantly improve the safety of the battery throughout its entire life cycle. Detailed Implementation

[0009] This section is used to illustrate the general implementation logic of the present invention. It only describes the implementation principles and application scenarios of the method and does not limit any specific materials, structures, preparation processes and parameters. Those skilled in the art can implement the invention using conventional technical means in the field based on the core logic disclosed in the present invention.

[0010] Example 1: Adaptation Implementation of a General Lithium-ion Battery System This embodiment is a general implementation of the present invention in a conventional lithium-ion battery, and the specific implementation logic is as follows: 16. In the electron transport path of the negative electrode of the target lithium-ion battery, a Schottky functional unit with unidirectional rectification characteristics is arranged so that the electron transport of the negative electrode must pass through the Schottky functional unit. 17. During charging, the reverse cutoff characteristic of the Schottky functional unit blocks the premature transport of electrons to the negative electrode active surface, thus preventing premature electron enrichment. After lithium ions migrate to the negative electrode active site and complete their insertion, the Schottky functional unit switches to the forward conduction state, allowing electrons to pass through synchronously and pair with the inserted lithium ions, achieving a timing match of "ion leader, electron lag," thereby suppressing lithium dendrite formation from the source. 18. During discharge, the Schottky functional unit remains in a positive low-resistance conduction state, and electrons flow back from the negative electrode active material to the current collector without hindrance, ensuring the normal discharge rate and power output of the battery.

[0011] This embodiment is compatible with all conventional lithium-ion battery systems, including consumer electronics batteries, energy storage batteries, power lithium batteries, and other applications across all scenarios.

[0012] Example 2: Implementation of Fast Charging Scenarios This embodiment is an implementation of the present invention in a high-rate fast charging scenario. The only difference from Embodiment 1 is that: according to the fast charging rate requirement of the target battery, a Schottky functional unit with corresponding rectification characteristics is matched so that the timing matching accuracy of lithium ion embedding and electron conduction during charging is adapted to the lithium ion migration rate of the fast charging scenario. In the 1C~6C full-rate fast charging scenario, the timing matching of "ion leader, electron lag" is always maintained, completely eliminating the generation of lithium dendrites in the fast charging scenario, while not affecting the fast charging efficiency and battery cycle life.

[0013] Example 3: Implementation of High-Rate Power Scenarios This embodiment is an implementation of the present invention in a high-rate power lithium battery. The only difference from Embodiment 1 is that, according to the high-rate charging and discharging requirements of the power lithium battery, a Schottky functional unit with a corresponding low forward voltage drop is matched. While ensuring charging timing control and suppressing lithium dendrites, the electronic transmission impedance during the discharge process is further reduced to meet the high power output requirements of the power lithium battery, and at the same time, the cycle life and safety of the power lithium battery are greatly improved.

Claims

1. A method for electronic timing control to suppress lithium dendrite formation in lithium batteries, characterized in that, Includes the following steps: A Schottky functional unit with unidirectional rectification characteristics is set in the electron transport path of the negative electrode of the lithium battery. During the charging process, the reverse cutoff characteristic of the Schottky functional unit is used to block the premature transport of electrons to the negative electrode active surface, thus preventing premature electron accumulation. After lithium ions migrate to the negative electrode active site and complete their insertion, the forward conduction characteristics of the Schottky functional unit allow electrons to pass through synchronously and pair with the inserted lithium ions, achieving a timing match of "ion leader, electron lag". This eliminates the timing difference between electron and lithium ion transport and suppresses lithium dendrite formation from the root. During discharge, the forward conduction characteristics of the Schottky functional unit are utilized to ensure that electrons flow back from the negative electrode active material to the current collector without obstruction, thus not affecting the battery's discharge performance.

2. The electronic timing control method for suppressing lithium dendrites in lithium batteries according to claim 1, characterized in that, The Schottky functional unit possesses intrinsic rectification characteristics of reverse cutoff and forward low-resistance conduction.

3. The electronic timing control method for suppressing lithium dendrites in lithium batteries according to claim 1, characterized in that, The method is applicable to all lithium-ion battery systems and is not limited by battery form, positive and negative electrode material system, or production process.

4. The electronic timing control method for suppressing lithium dendrites in lithium batteries according to claim 1, characterized in that, The method is adaptable to 1C~6C full-rate fast charging scenarios, and maintains the timing matching of electrons and lithium ions throughout the fast charging process, preventing the formation of lithium dendrites during fast charging.

5. A lithium-ion battery using the method according to any one of claims 1-4, characterized in that, The negative electrode electron transport path of the lithium-ion battery is provided with a Schottky functional unit that has unidirectional rectification characteristics.

6. The lithium-ion battery according to claim 5, characterized in that, The lithium-ion batteries include consumer electronics lithium batteries, energy storage lithium batteries, and power lithium batteries.

7. A battery module, characterized in that, It includes the lithium-ion battery as described in claim 5.

8. A battery pack, characterized in that, It includes the lithium-ion battery of claim 5 or the battery module of claim 7.

9. An electrical appliance, characterized in that, It includes the lithium-ion battery of claim 5, the battery module of claim 7, or the battery pack of claim 8.