All-solid-state multistage gradient biomimetic coupling battery structure

Abstract

This invention discloses an all-solid-state multi-level gradient biomimetic coupling battery structure, relating to the field of all-solid-state lithium battery technology. It includes gradient sandwich cells, staggered close-packed stacks, a thermo-pressed solid structure layer, distributed tabs, and a standardized casing. The unit electrodes and solid electrolyte are gradient-mirror matched, the stacked structure is staggered and interlocked, and the overall shape is regular. The thermo-pressing process achieves seamless interlayer bonding. This invention solves the problems of high interface impedance, poor contact, and poor structural adaptability in all-solid-state batteries, while possessing high ion transport efficiency, excellent mechanical stability, and high safety. It is compatible with standardized casings and mass production lines, possessing extremely high industrial application value for all-solid-state lithium batteries.

Description

Technical Field

[0001] This invention relates to the field of all-solid-state lithium battery structure technology, specifically to an all-solid-state multi-level gradient biomimetic coupling battery structure, adapted to multi-level gradient biomimetic composite positive and negative electrodes and multi-level gradient biomimetic composite solid electrolyte, belonging to the core structure technology of high-performance all-solid-state lithium batteries. Background Technology

[0002] Existing all-solid-state battery structures mostly follow the traditional liquid battery winding and stacking design, without dedicated structural optimization for the characteristics of solid electrolytes and multi-level gradient biomimetic electrodes. This generally results in the following technical defects: First, the simple flat stacking of layers leads to uneven interfacial contact pressure, making the interface between the solid electrolyte and electrode prone to voids, delamination, and cracking, resulting in extremely high interfacial impedance and a significant decrease in ion transport efficiency. Second, the lack of gradient-coupled structural design means that the gradient characteristics of the electrode and solid electrolyte cannot be matched, leading to disordered ion transport paths, severe concentration polarization and interfacial polarization, and limited rate performance and cycle life. Third, poor structural mechanical adaptability, failing to buffer volume deformation during electrode charging and discharging, and prone to structural failure and lithium dendrite puncture problems during long-term cycling. Fourth, insufficient overall structural regularity, high packaging difficulty, incompatibility with existing standardized casings and module layouts, and weak industrial adaptability. Current research on all-solid-state battery structures focuses only on optimizing a single dimension, such as stacking methods or packaging processes. It has not achieved a systematic biomimetic coupling design of multi-level gradient electrodes and solid electrolytes, and cannot solve the core problems of poor interface contact, high impedance, insufficient mechanical stability, and weak industrial adaptability. As a result, it is difficult to meet the application requirements of high-safety, high-rate, and long-life all-solid-state lithium batteries. Summary of the Invention

[0003] Technical issues To address the shortcomings of existing technologies, this invention provides an all-solid-state multi-level gradient biomimetic coupling battery structure, which solves the technical problems of poor interface contact, high interlayer impedance, poor gradient coupling, insufficient mechanical stability, and weak compatibility of packaging and arrangement in existing all-solid-state batteries. It achieves seamless bonding between the electrode and the solid electrolyte interface and efficient conduction of ion gradient, thereby improving the cycle stability, rate performance, and safety and reliability of all-solid-state batteries, while ensuring a regular structure and compatibility with standardized casing installation. Technical solution A fully solid-state multi-level gradient biomimetic coupling battery structure The "bionic" structure described in this invention continues to mimic the structural features of biological tissues, such as three-dimensional fiber interweaving, interlayer interlocking, and gradient synergistic transport, to achieve flexible mechanical adaptation between layers of all-solid-state batteries, directional gradient conduction of ions, and tight, gapless interface bonding. The all-solid-state multi-level gradient biomimetic coupling battery structure includes an all-solid-state gradient sandwich unit, a biomimetic staggered dense stack, an integrated hot-pressed solid structure layer, distributed solid current collector tabs, and a standardized packaging shell. The overall structure is a standard cuboid shape, with a regular shape without protrusions or misalignments, and a dimensional tolerance of ≤±2mm. It can directly adapt to the mainstream all-solid-state battery standardized shell and module layout without the need to modify the production line. All-solid gradient sandwich unit As the core electrochemical unit of the battery, it is composed of a multi-level gradient biomimetic composite positive electrode, a multi-level gradient biomimetic composite solid electrolyte, and a multi-level gradient biomimetic composite negative electrode that are tightly bonded together in sequence. The gradient directions of the three are completely mirror-aligned, forming a continuous and interconnected ion gradient transport channel. There is no liquid medium between the unit layers, the overall thickness is 60–200μm, and the dimensional consistency tolerance is ≤±4μm, eliminating the safety hazards of leakage and gas expansion from the source. Bionic staggered dense stacked body It is composed of multiple all-solid gradient sandwich units that are biomimetically staggered and densely stacked along the thickness direction. Adjacent units are staggered laterally by 15-30% and staggered longitudinally by a slight tilt angle of 2-5°, forming an interlocking structure between layers. The outer contour boundaries are kept aligned and regular throughout the stacking process, ultimately forming a standard cuboid stack with 30-220 stacked layers and an overall thickness of 3-45mm. This staggered structure can disperse interlayer stress, improve interlayer contact density, avoid interface delamination and cracking, and at the same time ensure the overall shape is regular and easy to install and arrange. Integrated hot-pressed solid structure layer Encased in the biomimetic staggered and densely stacked body, it is integrally hot-pressed under high temperature and high pressure. The hot-pressing temperature is 90–130℃ and the pressure is 1.0–2.5MPa. This process eliminates the tiny gaps between layers, strengthens the interlayer interface bonding force, and makes the all-solid gradient sandwich unit form an inseparable whole structure. This improves the structural mechanical stability and vibration and impact resistance, and eliminates interlayer slippage and cracking problems. Distributed solid-state collector tabs The design employs a multi-point distributed welding system, with positive and negative tabs symmetrically distributed on both sides of the stack. There are 2–5 tabs on each side. The tabs are made of copper-nickel composite foil and titanium alloy composite strip, with a thickness of 60–220μm and a width of 8–25mm. This design achieves uniform current distribution, eliminates local current concentration and hot spots, reduces interface polarization, and improves battery thermal stability and charge / discharge efficiency. Standardized packaging shell It adopts two standardized shells: a conventional square aluminum shell and a flexible composite encapsulation shell, which are precisely adapted to the overall standard cuboid shape of the battery. The inner wall of the shell has a micro gap to accommodate the deformation of the battery's charge and discharge capacitance. The encapsulation process uses liquid-free vacuum sealing to prevent moisture and impurities from entering. There is no need to customize irregular shells, resulting in low cost, high encapsulation efficiency, and full compatibility with existing battery installation, layout, and module integration processes. Impurity and Interface Control: Each component is purified and impurity removed before structural assembly. Solid particulate impurities and free water are strictly controlled to avoid impurity residues causing interfacial side reactions and local micro-short circuits, thus ensuring the long-term performance and safety of the battery. The interlayer interface is pretreated and activated to improve the bonding force between the solid electrolyte and the electrode interface and further reduce the interfacial impedance. Structural Adaptation and Working Principle This structure is fully coupled with a multi-level gradient biomimetic composite solid electrolyte and gradient electrodes. The interlocking structure formed by the staggered stacking ensures continuous and uniform contact between layers. Combined with the integrated hot-pressing curing process, it completely solves the problem of poor contact at the solid interface. When the battery is working, under the drive of the electric field, ions are directionally transported along the gradient channels of the positive and negative electrodes and the solid electrolyte, without concentration polarization. Mechanically, the interlocking interlayer and the hot-pressed overall structure buffer the volume deformation of the electrodes and effectively suppress lithium dendrite growth and puncture. At the same time, the standard shape meets the requirements of mass production and installation. Beneficial effects Biomimetic coupling gradient design: The all-solid-state gradient sandwich unit achieves gradient mirror matching between the electrode and the solid electrolyte, constructs a continuous ion gradient transport channel, significantly reduces interface impedance and polarization, and significantly improves battery rate performance and charge / discharge efficiency. Stable and reliable interlayer contact: Biomimetic staggered dense stacking + integrated hot pressing curing forms an interlocking integral structure with uniform and dense interlayer contact, completely solving the problems of voids, delamination and cracking at solid interfaces, resulting in excellent structural mechanical stability and vibration and impact resistance. With a regular shape and strong adaptability: the regularity of the outer contour is controlled throughout the process. The whole is a standard cuboid, which can be directly adapted to standardized packaging shells and module installation layouts. No customized design or production line modification is required. It has extremely strong industrial adaptability and reduces production and application costs. Safety performance is comprehensively improved: liquid electrolyte-free, vacuum-sealed packaging eliminates the risk of leakage and thermal runaway. The staggered structure and interface optimization effectively suppress lithium dendrites and strictly control impurity residues, providing dual protection for the long-term safe operation of the battery from both structural and process perspectives.

Claims

1. A full solid-state multistage gradient biomimetic coupled battery structure, characterized in that, It includes an all-solid-state gradient sandwich unit, a biomimetic staggered dense stack, an integrated hot-pressed solid structure layer, distributed solid current collector tabs, and a standardized packaging shell; the overall shape is a standard cuboid with a dimensional tolerance of ≤±2mm. The all-solid-state gradient sandwich unit is composed of a multi-level gradient biomimetic composite positive electrode, a multi-level gradient biomimetic composite solid electrolyte, and a multi-level gradient biomimetic composite negative electrode, which are sequentially bonded together, with the gradient directions of the three being mirror-aligned.

2. The all-solid-state multi-level gradient biomimetic coupling battery structure according to claim 1, characterized in that, The overall thickness of the all-solid gradient sandwich unit is 60–200 μm, and the dimensional consistency tolerance is ≤ ±4 μm.

3. The all-solid-state multi-level gradient biomimetic coupling battery structure according to claim 1, characterized in that, The biomimetic staggered dense stack is composed of multiple all-solid gradient sandwich units that are staggered laterally by 15–30% and staggered longitudinally by a slight tilt angle of 2–5°. The number of stacked layers is 30–220, the overall thickness is 3–45 mm, and the outer contour of the stack is aligned and regular throughout.

4. The all-solid-state multi-level gradient biomimetic coupling battery structure according to claim 1, characterized in that, The integrated hot-pressed solid structure layer is hot-pressed at a temperature of 90–130℃ and a pressure of 1.0–2.5MPa to solidify the stacked body into an integral structure.

5. The all-solid-state multi-level gradient biomimetic coupling battery structure according to claim 1, characterized in that, The distributed solid-state current collector has 2–5 tabs on each side, made of copper-nickel composite foil or titanium alloy composite strip, with a thickness of 60–220μm and a width of 8–25mm.

6. The all-solid-state multi-level gradient biomimetic coupling battery structure according to claim 1, characterized in that, The standardized packaging shell is a square aluminum shell or a flexible composite packaging shell, using a liquid-free vacuum sealing process.

7. The all-solid-state multi-level gradient biomimetic coupling battery structure according to claim 1, characterized in that, There is no liquid medium inside the battery, and the assembly components strictly control free water and solid impurities.