A high-safety long-service-life super-charging power battery based on a trinity energy storage mechanism

Abstract

The application discloses a trinity high-safety super-charging power battery, which is characterized by electrode material optimization and structure design, three energy storage mechanisms in the same electrode, 6C super-charging, 9-minute charging to 80%, no lithium precipitation, no collapse, no gas production, capacity retention rate of 10000 times of normal temperature cycle is greater than or equal to 80%, energy density of the battery cell is 215-220 Wh / kg, full industrial chain localization, suitable for existing lithium battery production line, and can be used for new energy vehicles and energy storage power stations.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion power battery technology, specifically involving a power battery that integrates a three-in-one energy storage mechanism within the same electrode and works collaboratively with a unified potential window, and achieves ultra-fast charging by relying on high intrinsic safety and long lifespan positive and negative electrode materials selected through multiple dimensions. In particular, it involves the core protection technology solutions of the positive electrode three-in-one energy storage architecture and the positive and negative electrode safety and long lifespan materials, which are suitable for automotive-grade applications in all scenarios such as new energy vehicles and energy storage power stations. Background Technology

[0002] Currently, lithium iron phosphate (LFP) power batteries face three major industry bottlenecks that cannot be simultaneously addressed: 1. Supercharging performance bottleneck: Traditional cathodes only employ a single-ion intercalation energy storage mechanism, resulting in slow kinetic response and inability to withstand high-rate instantaneous currents. The lack of a unified potential window for multi-mechanism collaborative design leads to significant supercharging polarization and limited charging speed. 2. Cathode safety and lifespan bottleneck: Conventional LFP materials are prone to iron ion dissolution, abnormal CEI film thickening, and electrolyte oxidation and gas generation at high rates and high potentials. Some ternary and manganese-based cathodes suffer from transition metal dissolution, structural collapse, and severe cycle gas generation, leading to a sharp drop in cycle life and increased thermal safety risks. 3. Anode safety and lifespan bottleneck: Traditional graphite anodes have a lithium intercalation potential close to 0V (vs Li / Li⁺), inevitably leading to lithium plating under high-current supercharging. Titanium-based and other non-lithium-plating anodes suffer from excessively high potentials and low energy density. Hard carbon / soft carbon anodes, before modification, suffer from pore collapse and aggravated gas generation.

[0003] Existing technologies cannot achieve in-situ synchronous coordination of three energy storage mechanisms—lithium-ion intercalation, double-layer capacitance, and pseudocapacitance—within the same electrode under a unified potential window. Nor can they systematically screen positive and negative electrode materials from six rigid dimensions—potential matching, no structural collapse, no gas generation and dissolution, 6C supercharging, independent controllability, and automotive-grade mass production—to meet the high safety and long life requirements of low gas generation, low metal dissolution, no lithium plating, and long cycle life under ultra-fast charging conditions. This is the technical problem that this invention urgently needs to solve. Summary of the Invention

[0004] I. Terminology Definitions (Clearly distinguish between potential and voltage to avoid confusion) 1. Potential: The electrode potential of a single electrode relative to a lithium metal reference electrode, expressed in V (vs Li / Li⁺), which is an inherent electrochemical characteristic of a single electrode; 2. Voltage: The potential difference between the positive and negative electrodes of a full cell, measured in volts (V), and labeled as V (full cell). It represents the operating characteristics of the full cell system.

[0005] II. Technical Problem to be Solved by the Invention To address the problems of insufficient supercharging capacity of existing power batteries, lack of a synergistic matching and screening system for positive and negative electrode materials, and the potential disturbances, lithium plating, gas generation, and structural collapse caused by multi-mechanism energy storage, this invention provides a high-safety, long-life supercharging power battery based on a three-in-one energy storage mechanism. First, the core ironclad rule of electrode selection is established and a unified potential window is anchored. Then, the optimal positive and negative electrode material system is determined through multi-dimensional screening. The three-in-one energy storage mechanism within the same electrode and the unified potential window work together as the core support for supercharging. High intrinsic safety and long-life positive and negative electrode materials serve as the core support for safety and lifespan, achieving a triple breakthrough in supercharging performance, safety performance, and cycle life.

[0006] III. The Core Iron Law of Electrode Selection The electrode design and material selection process of this invention follows four core principles: all materials are designed to fit a unified potential window, without reverse potential locking or capacity limitation. 1. The double-layer capacitor and pseudocapacitive energy storage mechanism are integrated simultaneously in the same electrode (positive electrode). The potential ranges of the two overlap throughout the anchoring window, with no potential loss. 2. The electrode material has a wide potential operating characteristic, precisely adapted to the anchored basic potential window of 2.5V~4.5V (vs Li / Li⁺), and the core cooperative potential window is 3.20V~3.50V (vs Li / Li⁺). 3. As the main body of the three-in-one energy storage mechanism, the cathode material meets the requirements of no conflicting electrochemical reactions within the window, no structural collapse, high conductivity, insolubility, and no gas generation; 4. The negative electrode only serves as the potential window anchoring function and does not have a three-in-one design to avoid potential disturbances caused by the dual positive and negative electrode mechanisms. It is required that the potential within the window is stable without lithium plating, compatible with 6C supercharging, long life, and independently controllable.

[0007] IV. Core Definition The three-in-one energy storage mechanism refers to the integration of three energy storage mechanisms within the same positive electrode: lithium-ion intercalation energy storage, double-layer capacitor energy storage, and pseudocapacitive energy storage. These three mechanisms achieve in-situ synchronous and coordinated charging and discharging within a unified coordinated potential window of 3.20V~3.50V (vs Li / Li⁺), without significant potential differences that cause internal friction or response mismatch. Among them, the double-layer capacitor is realized by physical adsorption of porous carbon, and the pseudocapacitive capacitor is realized by reversible oxidation-reduction of oxygen / nitrogen groups on the surface of doped porous carbon. The potential ranges of the two naturally overlap within the basic window of 2.5V~4.5V (vs Li / Li⁺), precisely adapting to the coordinated window requirements.

[0008] V. Core Principles of Tripartite Collaboration The key to the three-in-one energy storage mechanism of this invention lies in the fact that the three energy storage mechanisms share a unified potential range of 3.20V~3.50V (vs Li / Li⁺), with the potential ranges completely overlapping and the charging and discharging potentials responding synchronously. Moreover, the polarization of each mechanism is extremely low, and there is no significant potential difference that could cause internal energy loss. The double-layer capacitor and pseudocapacitor respectively handle instantaneous large currents and stabilize the potential at nanosecond and microsecond levels. The lithium-ion intercalation completes energy supply and long-term cycling at millisecond level. The three mechanisms form a dynamic mutual charging balance under high-current charging and discharging conditions. This process has no harmful internal energy loss and effectively suppresses large voltage fluctuations caused by single-mechanism charging and discharging on a macroscopic level, further enhancing potential stability. It achieves efficient and conflict-free synergy from the perspective of electrochemical principles and engineering applications, fundamentally solving the industry problems of large polarization, rapid cycle decay, and poor safety of traditional single-intercalation batteries during ultra-fast charging.

[0009] The electrochemical feasibility of this synergistic mechanism is guaranteed by both the iron law of electrode selection and the material screening system: the potential range of the positive electrode material is completely aligned with the synergistic window, and the negative electrode material only anchors the potential and does not participate in multi-mechanism energy storage, thus avoiding potential disturbances at the system level and ensuring 100% release of the efficiency of the three-in-one mechanism.

[0010] VI. The intrinsic logic of safe and long-lasting materials This invention utilizes a single-crystal modified LFP cathode and a low-potential, lithium-free, closed-pore modified hard carbon anode, determined through multi-dimensional screening, to achieve high safety and long lifespan throughout the entire material lifecycle. The cathode suppresses side reactions, gas generation, and metal dissolution through its single-crystal structure and low upper limit synergistic potential. The anode eliminates lithium deposition from the thermodynamic root by using a closed-pore disordered layer structure and a minimum lithium intercalation potential of 0.05V (vs Li / Li⁺). At the same time, both the cathode and anode meet the requirements of no structural collapse, no circulating gas generation, and high conductivity, achieving a perfect match between lifespan and kinetic performance, thus realizing system-level safety and longevity in ultra-fast charging scenarios. Technical solution

[0011] 1. Cathode material: Single-crystal / nano-carbon coated modified lithium iron phosphate (LiFePO4, LFP) After a systematic screening process based on six dimensions—potential matching, absence of structural collapse, absence of gas production and dissolution, 6C supercharging, independent controllability, and automotive-grade mass production—and elimination of materials such as lithium cobalt oxide, ternary lithium, and manganese-based materials that are prone to dissolution, gas production, and structural instability, LFP was identified as the sole optimal solution for the cathode. Its rated reversible operating potential range of 2.5V~3.8V (vs Li / Li⁺) perfectly matches the 2.5V~4.5V (vs Li / Li⁺) basic window and precisely matches the 3.20V~3.50V (vs Li / Li⁺) synergistic window. The core performance parameters are as follows: - Potential characteristics: Average lithium insertion / extraction plateau potential 3.45V±0.02V (vs Li / Li⁺), extremely stable charge / discharge plateau, 1C rate polarization ≤50mV, no potential hysteresis within the cooperative window; - Specific capacity characteristics: Stable and reversible specific capacity of 155~160mAh / g (1C / 25℃) in mass production, capacity retention of ≥85% at 6C rate, and first coulombic efficiency of ≥95.0%; - Structural and safety characteristics: olivine-type zero-strain Pnma space group three-dimensional rigid framework, no irreversible structural collapse within 2.5V~3.8V (vsLi / Li⁺), crystal phase retention rate ≥99.5% after 15,000 cycles; Fe ion dissolution rate ≤5ppb throughout the entire life cycle, gas production rate decreases by more than 70% after 1,000 cycles at 45℃, thermal decomposition temperature ≥480℃, no intrinsic risk of thermal runaway; - Kinetics and mass production characteristics: After nano-carbon coating and trace Mg doping, the electronic conductivity is ≥10⁻³S / cm, and the lithium-ion diffusion coefficient is ≥10⁻¹. 0 cm² / s, 6C charge / discharge polarization ≤200mV; more than 90% of the global production capacity is concentrated in China, with tens of millions of tons of automotive-grade mass production, yield rate ≥99%, patents are completely independent and controllable, and the entire industrial chain is domestically produced without risk.

[0012] The cathode adopts a single-layer homogeneous dispersed gradient-free structure, with modified LFP as the main body for lithium-ion intercalation energy storage, and ordered mesoporous carbon OMC and high nitrogen-doped porous carbon N-PCN as double-layer / pseudocapacitive energy storage units. The total mass ratio of OMC and N-PCN is 0.45%, which is nanoscale dispersed in the gaps between LFP particles. The potentials of the two overlap throughout the synergistic window of 3.20V~3.50V (vs Li / Li⁺), forming a dynamic energy replenishment balance with LFP without losing the proportion of cathode active material, thus ensuring maximum energy density.

[0013] 2. Anode material: Hard carbon (HC) with controllable closed-pore structure. After a systematic screening process based on six dimensions—low potential without lithium plating, no structural collapse, no gas generation and dissolution, 6C supercharging, independent controllability, and automotive-grade mass production—materials with low energy density, prone to gas generation, and structural instability, such as titanium-based, alloyed, and open-pore hard carbon, were eliminated, closed-pore modified hard carbon was identified as the only optimal solution for the anode material. It is currently the lowest potential thermodynamically absolutely lithium-plating-free carbon-based material, serving only the function of potential anchoring and not requiring a three-in-one design. Its core performance parameters are as follows: - Potential characteristics: Rated reversible operating potential range is 0.05V~1.2V (vs Li / Li⁺), average lithium intercalation plateau potential is 0.1V (vs Li / Li⁺), minimum lithium intercalation potential is higher than 0V (vs Li / Li⁺) and 50mV safety redundancy is reserved. After pairing with positive electrode LFP, the rated voltage of the full cell is 3.2~3.3V (full cell), and the potential difference is stable without inversion; - Specific capacity characteristics: Stable reversible specific capacity in mass production ~400mAh / g (1C / 25℃), 6C rate capacity retention ≥88%, first coulombic efficiency ≥90%, and specific capacity far exceeds that of traditional graphite anodes; - Structural and safety characteristics: Disordered layer + closed nanopore hierarchical structure, charge and discharge volume change rate ≤10% and completely reversible, structure retention rate ≥99% after 10,000 cycles, no irreversible collapse; pure carbon-based with no transition metals, zero dissolution, gas production rate ≤1.2% after 1,000 cycles at 45℃, thermodynamically eliminating lithium plating, and no lithium dendrite formation even at 6C overcharge and -40℃ low temperature; - Kinetics and mass production characteristics: After modification, the electronic conductivity reaches 10⁻³~10⁻² S / cm, and the lithium-ion diffusion coefficient reaches 10⁻ 9 ~10⁻ 8 cm² / s, 6C charge / discharge polarization ≤180mV; domestic production of automotive-grade lithium batteries at the 10,000-ton level has been achieved, the closed-cell modification technology is completely independent and controllable, raw materials and production equipment are all domestically produced, the cost is controllable and compatible with existing lithium battery production lines.

[0014] The negative electrode undergoes 3% precise pre-lithiation treatment, with an N / P ratio of 1.25~1.30:1, a soft carbon coating thickness of 60nm, and a closed-pore rate of 65~70%. This not only compensates for the loss of active lithium and raises the working potential, but also further inhibits electrolyte penetration and SEI film damage, ensuring potential stability under overcharge conditions. It perfectly matches the kinetics and cycle life of the positive electrode LFP, with no system shortcomings.

[0015] 3. Full battery system matching The full battery operates at a voltage of 2.75V~3.40V (full battery), which is mathematically consistent with the potential range of the positive and negative electrodes, with no overcharging or over-discharging. The three-in-one energy storage mechanism of the positive electrode forms a dynamic energy replenishment balance within a synergistic window of 3.20V~3.50V (vs Li / Li⁺), achieving the core efficiency and potential stability of 6C supercharging. The closed-pore modified hard carbon of the negative electrode anchors the potential and ensures safety without lithium plating. Both the positive and negative electrodes are high intrinsic safety materials without structural collapse or gas dissolution, achieving a system-level closed loop of supercharging, safety, lifespan, energy density, mass production, and independent controllability. Beneficial effects

[0016] 1. Three-in-one energy storage mechanism + precise material matching: 6C supercharging ultimate realization The three energy storage mechanisms within the same positive electrode completely overlap within a unified synergistic potential window of 3.20V~3.50V (vs Li / Li⁺), and the charge and discharge potentials respond synchronously. Under high current, a dynamic mutual charging energy balance is formed. Combined with selected high-conductivity positive and negative electrode materials, the high current response rate is increased by more than 10 times. At 25℃, the time to charge from 0 to 80% SOC at 6C constant current is ≤9 minutes, and the charge and discharge polarization fluctuation is ≤200mV. This completely breaks through the LFP supercharging dynamics bottleneck and there is no capacity loss.

[0017] 2. Multi-dimensional screening of positive and negative electrode materials: maximizing intrinsic safety. The positive electrode is modified LFP with zero dissolution, extremely low gas production, and zero strain structure. The negative electrode is modified hard carbon with closed pores, which has absolutely no lithium plating, zero metal dissolution, and no gas production during cycling. Both have excellent thermal stability and do not catch fire or explode in automotive-grade needle penetration, extrusion, overcharge, and thermal abuse tests. This addresses the safety concerns of superchargeable batteries from the intrinsic properties of the materials, rather than relying on the BMS as a fallback.

[0018] 3. Perfectly matched positive and negative electrode lifespan: Achieving ultra-long cycle life. The positive electrode modified LFP retains ≥80% capacity after 15,000 cycles at room temperature, and the negative electrode closed-cell modified hard carbon retains ≥80% capacity after 10,000 cycles at room temperature. Under 6C supercharging conditions, both achieve ≥80% capacity retention after 4,000 cycles, meeting the automotive-grade 8-year / 150,000 km warranty requirements. There is no structural collapse or aggravation of side reactions throughout the entire life cycle, making it suitable for long-life scenarios such as energy storage and heavy trucks.

[0019] 4. Maximizing the proportion of active substances: Energy density reaches the LFP ceiling. The positive electrode adds only 0.45% capacitor carbon to achieve a three-in-one mechanism, and 99.55% is high specific capacity modified LFP. The negative electrode is closed-pore modified hard carbon with a specific capacity far exceeding that of graphite. The actual mass production energy density of the full cell reaches 215~220Wh / kg, which is close to the medium nickel 5-series ternary 3.2~3.3V (full cell) system. Moreover, there is no risk of dissolution and thermal runaway of ternary materials, and the cost is more than 30% lower than that of ternary materials.

[0020] 5. Domestic production across the entire industry chain: self-reliant and controllable Both positive and negative electrode materials are selected through independent and controllable screening. The core technology, patents, raw materials, and production equipment are all domestically produced, with no overseas barriers. The yield rate of automotive-grade mass production is ≥97%, which can be directly compatible with existing lithium battery production lines without the need for large-scale equipment modification. The industrialization speed is fast and the cost is controllable. Detailed Implementation Example

[0021] 1. Preparation of high-safety cathode Using Mg²⁺ / Zr 4The lithium-ion intercalation substrate is a single-crystal LFP with dual doping, nano-Al2O3 coating, and nano-carbon coating, combined with ordered mesoporous carbon OMC and high-nitrogen-doped porous carbon N-PCN. The slurry is prepared by phase separation premixing and sand-free milling process. The total mass ratio of OMC and N-PCN is 0.45%, which is nano-dispersed in the gaps between LFP particles. The slurry fineness is ≤8μm and the dispersion uniformity is ≥99.5%. The positive electrode has a compaction density of 2.5~2.6g / cm³, a rated reversible working potential range of 2.5V~3.8V (vs Li / Li⁺), and a core synergy window of 3.20V~3.50V (vs Li / Li⁺). The three energy storage mechanisms completely overlap in the potential range within the synergy window, forming a dynamic mutual charging energy balance, and realizing in-situ synchronous synergistic charging and discharging.

[0022] 2. Preparation of high-safety anode The hard carbon with controllable closed-pore modification, achieved by steam pore expansion, low-temperature plasma precision pore opening, and soft carbon coating, has a closed-pore rate of 68% and a soft carbon coating thickness of 60nm. It undergoes 3% precise pre-lithiation treatment, resulting in an N / P ratio of 1.28:1. The rated reversible working potential range of the negative electrode is 0.05V~1.2V (vs Li / Li⁺), with an average lithium intercalation plateau potential of 0.1V (vs Li / Li⁺). It exhibits absolute no lithium plating thermodynamically and a polarization of ≤180mV at 6C charge / discharge.

[0023] 3. Cell Assembly and Performance The above-mentioned positive and negative electrode sheets, along with a polyethylene separator and EC / EMC / DMC system lithium-ion electrolyte, were assembled into a square soft-pack battery cell. The full cell operating voltage is 2.75V~3.40V (full cell), and the rated voltage is 3.3V (full cell). The actual measured performance of the battery cell is as follows: - Supercharging performance: 0~80% SOC is achieved in 9.3 minutes at 25℃ with 6C constant current charging; 86% capacity retention at 6C rate; voltage fluctuation amplitude ≤200mV under high current; excellent potential stability. - Cycle life: 83.2% capacity retention after 10,000 cycles at 25℃ and 6C overcharge, 81.5% capacity retention after 4,000 cycles, with no lithium plating, gas generation, or structural collapse throughout the cycle; - Safety performance: The cell thickness expansion rate is ≤3.5% after 1000 cycles at 45℃, the Fe ion dissolution is ≤4ppb, and it does not catch fire, explode, or leak after automotive-grade mandatory safety tests (needle penetration, extrusion, overcharge, and thermal abuse). - Energy density: The actual mass production energy density of the battery cell is 218Wh / kg, which is the ceiling of the LFP 3.2~3.3V (full cell) system and close to the medium nickel 5-series ternary system.

[0024] The positive and negative electrode materials in this embodiment are both automotive-grade mass-production systems, with the entire industry chain being domestically produced. They can be directly and massively applied to scenarios such as new energy passenger vehicles and energy storage power stations.

Claims

1. A power battery, characterized in that, The battery includes a positive electrode, a negative electrode, a separator, and an electrolyte. The battery has a three-in-one energy storage mechanism, which integrates lithium-ion intercalation energy storage, double-layer capacitor energy storage, and pseudocapacitive energy storage within the same electrode. The three energy storage mechanisms achieve in-situ synchronous and coordinated charging and discharging within a unified potential window, without significant potential differences that cause internal losses, and form a dynamic mutual charging energy balance under high current charging and discharging conditions.

2. The power battery according to claim 1, characterized in that, The three-in-one energy storage mechanism is located at the positive electrode; the uniform potential window of the positive electrode is 3.20V ~ 3.50V (vs Li / Li⁺).

3. The power battery according to claim 2, characterized in that, The cathode uses single-crystal nano-carbon coated LFP as the lithium-ion intercalation energy storage body, and ordered mesoporous carbon OMC and high nitrogen-doped porous carbon N-PCN as capacitor energy storage units; the total mass ratio of OMC and N-PCN is 0.45%, which is nanoscale dispersed in the gaps between LFP particles, so that the three energy storage mechanisms overlap within the potential range of the unified potential window, form a dynamic energy replenishment balance, and work together without internal friction.

4. The power battery according to claim 2, characterized in that, The positive electrode LFP is Mg²⁺ / Zr. 4 The structure consists of a dual-element bulk doped and wet-processed nano-Al2O3 coating with a particle size of 1~3μm and a rated reversible working potential range of 2.5V~3.8V (vsLi / Li⁺).

5. The power battery according to claim 1, characterized in that, The negative electrode uses composite closed-cell hard carbon material, which is coated with soft carbon and precisely pre-lithiated. The N / P ratio is 1.25~1.30:1, and its rated reversible working potential range is 0.05V~1.2V (vs Li / Li⁺). The risk of lithium plating is controllable, the cycle life is long, and it only serves the function of potential anchoring.

6. The power battery according to claim 1, characterized in that, The positive electrode is made of single-crystal nano-carbon coated modified lithium iron phosphate material, and the negative electrode is made of hard carbon material with controllable pore size and closed pores.