A high-safety long-endurance solid-state lithium battery system for low-altitude flying robots

Abstract

The application belongs to the technical field of batteries, and in particular relates to a high-safety long-endurance solid-state lithium battery system for a low-altitude flying robot, which comprises a solid-state cell array, an interface self-adaptive regulation and control module, a distributed coupling management module, a multi-source state sensing network, an edge intelligent control unit and a communication and power interface module; the interface contact is maintained in cooperation with an elastic support grid through a piezoelectric actuator, thermal homogenization is realized by combining a phase change material with a micro-channel liquid cooling, and power is dynamically scheduled and fault cells are isolated based on multi-source sensing fusion. The piezoelectric actuator and the elastic support grid are cooperated to maintain the physical contact integrity of the solid-state electrode / electrolyte interface under the dynamic working condition of the aircraft, so that the interface impedance is prevented from suddenly increasing due to the expansion of micro-cracks.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, specifically a high-safety, long-endurance solid-state lithium battery system for low-altitude flying robots. Background Technology

[0002] With the rapid development of the low-altitude economy, low-altitude flying robots are increasingly widely used in various scenarios. Such aircraft have stringent requirements for energy systems, which must have both high energy density to support long flight time and extreme safety to avoid thermal runaway accidents. Solid-state lithium batteries, with their advantages of high intrinsic safety, high theoretical energy density and wide operating temperature range, are regarded as the ideal choice for the next generation of aviation power sources and have gradually entered the engineering exploration stage.

[0003] Currently, most mainstream low-altitude flying robots use liquid electrolyte lithium-ion battery systems. Although a balance between safety and range is achieved through various means, the flammable solvents in liquid systems can easily induce thermal runaway under abnormal operating conditions, making it difficult to meet aviation-grade safety standards. As a result, the industry has turned to oxide or sulfide-based solid electrolytes to build all-solid-state batteries. These batteries can physically isolate the positive and negative electrodes, improve thermal stability, and are compatible with high-voltage positive electrodes. Some solutions integrate solid-state cells into modular battery packs, supplemented by passive heat dissipation and basic monitoring, which has initially verified the feasibility of using them in lightweight drones.

[0004] There are deep-seated technical contradictions in existing solid-state lithium battery systems. The dynamic sensitivity of the solid electrolyte interface impedance is in fundamental conflict with the power output stability requirements of flying robots under varying operating conditions. Vibrations and temperature fluctuations during flight can easily lead to micro-cracks or debonding at the interface, causing a sudden increase in impedance, performance degradation, and even power interruption. Overly reinforced packaging will increase the system weight, offset the energy density advantage of solid-state batteries, and violate the original intention of long-endurance design.

[0005] Therefore, the present invention provides a high-safety, long-endurance solid-state lithium battery system for low-altitude flying robots. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0007] The technical solution adopted by this invention to solve its technical problem is: a high-safety, long-endurance solid-state lithium battery system for low-altitude flight robots, comprising: Solid-state battery cell array is composed of multiple solid-state individual cells connected in series and parallel. Each solid-state individual cell includes a positive electrode composite layer, a solid electrolyte layer, a negative electrode composite layer and current collectors on both sides. The positive electrode / electrolyte interface is provided with a buffer layer, and each cell is encapsulated in a housing with an elastic support grid inside the housing. An interface adaptive control module is embedded in the housing of each cell package. It includes a piezoelectric actuator array, a local current density sensor and a real-time interface impedance monitoring circuit. The piezoelectric actuator drive end is coupled to the elastic support grid and applies high-frequency micro-amplitude vibration in response to abnormal interface impedance or current density signals to repair interface debonding. The distributed coupling management module, arranged around the solid-state battery cell array, includes a phase change material filling cavity, a microchannel liquid cooling circuit embedded therein, a strain release hinge structure set at the connection between the battery pack and the aircraft frame, and a thermal expansion compensation mechanism installed on the lateral constraint frame of the battery cell array. The multi-source state sensing network includes a temperature gradient sensor array, a triaxial vibration accelerometer, a barometric altimeter, a cell voltage / current sampling unit, and an insulation resistance monitoring circuit. The edge intelligent control unit has a built-in interface degradation prediction model trained based on historical flight data, which initiates the cell isolation procedure when irreversible interface degradation is detected. The communication and power interface module includes dual redundant CAN communication channels, a high-voltage DC output terminal with overcurrent and overtemperature protection, and an emergency power-off relay controlled by both the flight control system and the edge intelligent control unit.

[0008] As a preferred embodiment, in the solid-state single cell, the positive electrode composite layer is formed by mixing and pressing a high-voltage nickel-manganese-cobalt oxide active material, a conductive carbon network and an ion-conductive polymer binder; the solid electrolyte layer is a dense sintered garnet-type oxide ceramic film; and the negative electrode composite layer is formed by combining a pre-lithiated silicon-carbon composite material with a flexible ion-conductive polymer matrix. Each functional layer is bonded at the interface through a low-temperature co-firing process, and the buffer layer at the positive electrode / electrolyte interface is an alumina layer formed by atomic layer deposition.

[0009] As a preferred embodiment, the elastic support mesh is woven from shape memory alloy wires.

[0010] As a preferred method, the interface impedance monitoring circuit periodically injects a broadband excitation signal during the non-power output period of the aircraft and analyzes the Nyquist diagram to extract the interface charge transfer resistance and diffusion impedance parameters. When the current density in the micro-area deviates from the reference value by more than a preset threshold, the piezoelectric actuator at the corresponding position is triggered to work.

[0011] As a preferred embodiment, the phase change material filling cavity is filled with a paraffin-based composite phase change material; The microchannel liquid cooling circuit is composed of flexible silicone tubes, with the internal circulation medium being a mixed solution of deionized water and ethylene glycol, and is connected to the heat dissipation fins on the outer wall of the machine. The thermal expansion compensation mechanism consists of a bimetallic strip and a sliding guide rail, which automatically adjusts the lateral constraint force according to temperature changes to avoid the accumulation of thermal stress.

[0012] As a preferred approach, in the multi-source state sensing network, a temperature gradient sensor array is used to construct a three-dimensional thermal field distribution model, and a triaxial vibration accelerometer is fixed at the center of the battery pack to collect the vibration spectrum of the machine body.

[0013] As a preferred approach, the interface degradation prediction model stored inside the edge intelligent control unit adopts a lightweight decision tree algorithm. The inputs include vibration spectrum, temperature gradient, current distribution non-uniformity and interface impedance parameters, and the output is a cell health status assessment. The total available power of the system is dynamically determined by the following formula: , in Related to local temperature and cooling capacity, It exhibits an exponential decay relationship with interface impedance and vibration intensity. It is modulated by both SOC and SOH.

[0014] As a preferred embodiment, in the communication and power interface module, the dual redundant CAN channels achieve fault switching through a hardware watchdog. The high-voltage DC output terminal integrates a temperature fuse and an overcurrent fuse.

[0015] As a preferred approach, a dynamic power scheduling and interface maintenance method for a high-safety, long-endurance solid-state lithium battery for low-altitude flight robots includes the following steps: Before the flight mission is launched, an initial set of thermal-mechanical management parameters is generated based on the flight path altitude profile, estimated flight time, load requirements and ambient temperature. During flight, multi-source sensing data is integrated to perform status assessment: if high-frequency impact vibration is detected, the activation sensitivity of the piezoelectric actuator is increased; if local hot spots are identified, the cooling flow rate in the corresponding area is increased; if the interface impedance is found to be continuously exceeding the standard and accompanied by abnormal current, the cell discharge rate is reduced and micro-vibration repair is initiated. Perform a full AC impedance spectroscopy scan during the low-power window to update the interface health database; When it is determined that a certain battery cell has undergone irreversible degradation, its series circuit is immediately cut off and the redundant branch is activated. At the same time, a power degradation warning is sent to the flight control system. After the task is completed, a battery health report is generated, which includes the cumulative number of repairs, the area of ​​maximum heat load, the trend of insulation performance, and the remaining capacity estimate.

[0016] The beneficial effects of this invention are as follows: The present invention discloses a high-safety, long-endurance solid-state lithium battery system for low-altitude flight robots. Through the synergistic effect of piezoelectric actuators and elastic support grids, the physical contact integrity of the solid electrode / electrolyte interface is maintained under the dynamic operating conditions of the aircraft, avoiding a sudden increase in interface impedance caused by the propagation of microcracks. By utilizing a composite thermal management mechanism of phase change materials and microchannel liquid cooling, the internal thermal field of the battery pack is homogenized without external forced air cooling, thus suppressing thermal stress-induced interface debonding. Early identification and local isolation of interface degradation based on multi-source sensing fusion are achieved to prevent single-point failures from evolving into system-level power interruptions. Under the combined disturbances of high-frequency vibration of the body and sudden changes in atmospheric temperature, the battery system can still output rated power stably; and through modular quick-swap structure and redundant communication design, the maintainability and mission continuity of the system are improved. Lightweight packaging and intelligent power scheduling strategies effectively balance the contradiction between safety redundancy and energy density, enabling solid-state lithium battery systems to meet aviation safety standards while supporting low-altitude flying robots to complete long-endurance operations. Attached Figure Description

[0017] The invention will now be further described with reference to the accompanying drawings.

[0018] Figure 1 This is a structural block diagram of a high-safety, long-endurance solid-state lithium battery system for low-altitude flying robots, as described in this invention. Detailed Implementation

[0019] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0020] like Figure 1 As shown, the embodiments of the present invention include a solid-state cell array, an interface adaptive control module, a distributed coupling management module, a multi-source state sensing network, an edge intelligent control unit, and a communication and power interface module; the modules form a closed-loop collaborative system through physical connections, electrical signal paths, and real-time data buses to jointly maintain the electrochemical stability and structural integrity of the battery system throughout its entire life cycle and under all flight profiles.

[0021] The solid-state battery array is composed of multiple solid-state individual cells integrated in series and parallel. Each solid-state individual cell adopts a stacked structure, including a positive electrode composite layer, a solid electrolyte layer, a negative electrode composite layer, and current collectors on both sides. The positive electrode composite layer is made of high-voltage nickel manganese cobalt oxide active material, conductive carbon network and ion-conductive polymer binder mixed and pressed. The solid electrolyte layer is a dense sintered garnet-type oxide ceramic film. The negative electrode composite layer is made of pre-lithiated silicon carbon composite material and flexible ion-conductive polymer matrix. Atomic-level interfacial bonding is achieved between the layers through a low-temperature co-firing process, and a nano-scale alumina buffer layer is introduced at the positive electrode / electrolyte interface to suppress interfacial side reactions. All solid-state single cells are encapsulated in a lightweight aluminum alloy casing, with a micron-scale elastic support mesh inside the casing. This mesh is woven from shape memory alloy wires and can undergo controllable deformation under temperature changes or mechanical stress to maintain constant contact pressure in the cell stacking direction.

[0022] The interface adaptive control module is embedded inside the packaging shell of each solid-state cell and includes a micro piezoelectric actuator array, a local current density sensor, and a real-time interface impedance monitoring circuit. The micro piezoelectric actuator array is uniformly distributed along the cell stacking direction, and its driving end is directly coupled to the elastic support grid. In response to the feedback signal output by the interface impedance monitoring circuit, it applies high-frequency micro-amplitude mechanical vibration to perform in-situ repair of the local debonding area. A local current density sensor is placed on the surface of the current collector and uses the Hall effect principle to detect abnormal current distribution in a micro-area. When the current density in a certain area deviates from the reference value by more than a preset safety threshold, the piezoelectric actuator at the corresponding position is triggered to work. The interface impedance real-time monitoring circuit uses four-wire AC impedance spectroscopy technology to periodically inject low-amplitude broadband excitation signals during the non-power output period of the aircraft, analyze the Nyquist diagram feature points of the electrode / electrolyte interface, extract the interface charge transfer resistance and diffusion impedance parameters, and upload the results to the edge intelligent control unit.

[0023] The distributed coupling management module consists of a phase change material filling cavity, a microchannel liquid cooling circuit, a strain release hinge structure, and a thermal expansion compensation mechanism. A phase change material filling cavity is arranged around the solid-state battery cell array. The cavity is filled with paraffin-based composite phase change material. The phase change temperature range covers the typical ambient temperature range of low-altitude flight and is used to absorb the instantaneous heat generated by the battery cells during the high-rate discharge stage. The microchannel liquid cooling circuit is made of flexible silicone tubes and embedded inside the phase change material cavity. The circulating medium inside the tube is a mixed solution of deionized water and ethylene glycol. Forced convection heat dissipation is achieved by external micro-pump. The inlet and outlet of the cooling circuit are connected to the heat dissipation fins on the outer wall of the aircraft. The strain release hinge structure is set at the connection between the battery pack and the aircraft frame. It adopts a two-degree-of-freedom universal joint design, which allows the battery pack to generate small angular displacements during the vibration of the aircraft without transmitting shear stress to the inside of the battery cells. The thermal expansion compensation mechanism consists of a bimetallic strip and a sliding guide rail, which is installed on the lateral constraint frame of the battery cell array. When the temperature changes cause the overall size to expand or contract, the bimetallic strip bends and drives the sliding guide rail to shift, automatically adjusting the lateral constraint force to avoid interface cracking caused by the accumulation of thermal stress.

[0024] The multi-source state perception network covers the entire battery system, including a temperature gradient sensor array, a triaxial vibration accelerometer, a barometric altimeter, a cell voltage / current sampling unit, and an insulation resistance monitoring circuit. The temperature gradient sensor array consists of multiple thermocouple nodes, which are respectively arranged on the cell surface, inside the phase change material cavity, and at the inlet and outlet of the cooling circuit to construct a three-dimensional thermal field distribution model. The triaxial vibration accelerometer is fixed at the center of the battery pack to collect the vibration frequency and amplitude of the body in the X, Y, and Z directions in real time. The barometric altimeter is integrated into the aircraft's main control system. Its output signal is synchronized to the edge intelligent control unit via a communication bus to calculate the ambient temperature and atmospheric density corresponding to the current flight altitude. The cell voltage / current sampling unit adopts an isolated differential amplifier circuit to sample the terminal voltage and branch current of each solid-state cell at the millisecond level. The insulation resistance monitoring circuit continuously monitors the insulation status between the battery pack casing and the internal high-voltage circuit using a DC injection method. Once the insulation resistance falls below the safety threshold, the protection mechanism is triggered.

[0025] The edge intelligent control unit is the core processing module. Its hardware platform is an embedded microcontroller based on the ARM Cortex-M7 core, with a built-in Trusted Execution Environment (TEE). All sensitive data processing is completed within this secure area. This unit is interconnected with the multi-source state perception network, the interface adaptive control module, and the main flight control system of the aircraft via a high-speed CAN bus, and communicates with the local monitoring circuit of each solid-state battery cell via the SPI interface. It internally stores a pre-trained interface degradation prediction model, which is constructed based on vibration spectrum, temperature gradient, current distribution and interface impedance correlation data collected in historical flight missions, and uses a lightweight decision tree algorithm to achieve online inference. Before each flight mission is launched, the edge intelligent control unit generates an initial thermal-mechanical management parameter set based on the current ambient temperature, preset flight path altitude profile and load requirements. During flight, it integrates multi-source sensing data in real time to dynamically adjust the pump speed of the microchannel liquid cooling circuit, the excitation frequency and amplitude of the piezoelectric actuator, and the upper limit of the discharge current of each cell. When the interface impedance of a certain battery cell is detected to be higher than the convergence judgment condition multiple times in a row and accompanied by abnormal local current density, the isolation procedure of the battery cell is immediately started, its series circuit is cut off and the redundant battery cell branch is enabled, and at the same time, a power degradation warning is sent to the flight control system.

[0026] The communication and power interface module includes dual redundant CAN communication channels, high-voltage DC output terminals, emergency power-off relays, and an electromagnetic shielding housing. The dual redundant CAN communication channels use independent physical lines and protocol stacks. One channel is the primary channel connecting to the flight control system, and the other is the backup channel connecting to the ground monitoring terminal. Fault switching between the two is achieved through a hardware watchdog. The high-voltage DC output terminals use aerospace-grade connectors, which integrate a temperature fuse and an overcurrent fuse. The power supply is automatically cut off when the output current exceeds the safety limit or the terminal temperature rises abnormally. The emergency power-off relay is dually controlled by the aircraft's main control system and the edge intelligent control unit. Any system can issue an emergency stop command to disconnect all battery cell outputs within milliseconds. The electromagnetic shielding shell is made of multiple layers of metal foil and conductive rubber composite, which encloses the entire battery system, effectively suppressing the influence of external radio frequency interference on the internal weak electrical signals and preventing electromagnetic radiation from the battery from interfering with the flight control system.

[0027] The solid-state battery array adopts a modular design, with each module containing eight solid-state individual cells. The modules are physically and electrically connected through quick-release mechanical latches and waterproof electrical connectors. The module shell has standard mounting holes for easy and quick replacement on different types of aircraft. Each module integrates an independent local BMS, which is responsible for equalization charging, temperature monitoring and fault reporting of the cells within the module. The local BMS and the edge intelligent control unit communicate via power line carrier communication, eliminating the need for additional wiring.

[0028] In terms of system workflow, before the flight mission is launched, the edge intelligent control unit first executes a self-test program to verify the status of each sensor, actuator and communication link; then it reads the flight path altitude, expected flight time and maximum load power in the flight plan, and, combined with the current ambient temperature, calls the thermal-power management parameter library to generate the initial control strategy; During flight, the multi-source state perception network uploads data at a fixed sampling period, and the edge intelligent control unit performs a state assessment every 100 milliseconds. If the vibration accelerometer detects a high-frequency impact event, the activation sensitivity of the piezoelectric actuator is immediately increased; If the temperature gradient sensor indicates the formation of local hot spots, increase the flow distribution of the cooling circuit in the corresponding area; If the interface impedance monitoring circuit identifies a degradation trend in the interface of a certain cell, it dynamically reduces its discharge rate and initiates micro-vibration repair. When the aircraft enters the hovering or low-speed cruise phase, the system uses this low-power window to perform a complete AC impedance spectrum scan and update the interface health status database. After the mission is completed, the edge intelligent control unit generates a battery health report for this flight, including the cumulative number of interface repairs, the maximum heat load area, and the trend of insulation performance changes, for use in subsequent maintenance decisions.

[0029] The solid-state battery array is composed of multiple solid-state individual cells integrated in series and parallel. Each solid-state individual cell adopts a stacked structure, including a positive electrode composite layer, a solid electrolyte layer, a negative electrode composite layer, and current collectors on both sides. The positive electrode composite layer is made of high-voltage nickel-manganese-cobalt oxide active material. Conductive carbon black SuperP and ion-conductive polymer binder polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) are mixed at a mass ratio of 85:10:5 and then rolled to form a compacted density of 3.2 g / cm³ and a thickness of 80 μm. The solid electrolyte layer is a densely sintered garnet-type oxide ceramic film. Its crystal phase is cubic, with a relative density ≥98%, a thickness of 40 μm, and a room temperature ionic conductivity of [missing information]. ; The negative electrode composite layer is made of pre-lithiated silicon-carbon composite material (Si content of 15wt%, first coulombic efficiency ≥92%) and flexible ion-conducting polymer matrix (PEO-LiTFSI system containing LiTFSI salt) in a mass ratio of 70:30, and the thickness is 60μm after hot pressing. Atomic-level interfacial bonding was achieved between the functional layers through a low-temperature co-firing process at 550°C for 2 hours, and an atomic layer deposition (ALD) alumina layer with a thickness of 5 nm was introduced at the cathode / electrolyte interface. A buffer layer is added to suppress interfacial side reactions and the risk of lithium dendrite penetration. All solid-state cells are encapsulated in a lightweight aluminum alloy housing with a wall thickness of 1.2 mm. The housing contains a micron-level elastic support mesh woven from nickel-titanium shape memory alloy wires (NiTi, martensitic phase transition temperature Ms=35℃) with a diameter of 50 μm and a mesh aperture of 200 μm. The mesh can undergo controllable deformation under temperature changes or mechanical stress to maintain a constant contact pressure in the cell stacking direction, with a target contact pressure range of 0.8-1.2 MPa.

[0030] The interface adaptive control module is embedded inside the package of each solid-state cell. It includes a micro piezoelectric actuator array, a local current density sensor, and a real-time interface impedance monitoring circuit. The micro piezoelectric actuator array is evenly distributed along the cell stacking direction, with a total of 12 actuation units. Each unit is 2mm×2mm×0.5mm in size and uses PZT-5H piezoelectric ceramic material. The resonant frequency is 25kHz. When a 150Vpp AC voltage is applied, it can generate a displacement output of ±0.5μm. Its driving end is directly coupled to the elastic support mesh through a silicone pad. The local current density sensor is arranged on the surface of the aluminum current collector, adopts the Hall effect principle, has a sensitive area of ​​1 mm², a range of 0-10 A / cm², a resolution of 0.1 A / cm², and a sampling frequency of 1 kHz. When the current density in a certain area deviates from the reference value (defined as the theoretical average value under the current discharge rate) by more than ±15%, the piezoelectric actuator at the corresponding position is triggered to work. The interface impedance real-time monitoring circuit uses four-wire AC impedance spectroscopy to periodically inject a wideband excitation signal with an amplitude of 10mV and a frequency range of 10mHz to 100kHz every 5 minutes during non-power output periods of the aircraft (such as hovering and gliding phases). It uses Fast Fourier Transform (FFT) to analyze the Nyquist plot feature points of the electrode / electrolyte interface, extracts the interface charge transfer resistance Rct corresponding to the high-frequency semicircle and the low-frequency Warburg diffusion impedance parameter σ, and uploads the results to the edge intelligent control unit via the SPI interface. Among them, Rct is calculated based on the equivalent circuit fitting model R(Q(RW)), and the fitting error is controlled within 5%.

[0031] The distributed coupling management module consists of a phase change material filling cavity, a microchannel liquid cooling circuit, a strain release hinge structure, and a thermal expansion compensation mechanism. The phase change material filling cavity is arranged around the solid-state cell array in a U-shaped encapsulation structure. It is filled with paraffin-based composite phase change material Paraffin-RT42 (melting point 42℃, latent heat of phase change 180kJ / kg), doped with 5wt% boron nitride nanosheets to improve the thermal conductivity to 1.8W / (m·K). The phase change temperature range covers the typical ambient temperature range of low-altitude flight (-10℃ to +50℃), and is used to absorb the instantaneous heat generated by the cell during the 3C discharge stage, with a maximum heat absorption rate of 15W / L. The microchannel liquid cooling circuit consists of flexible silicone tubes with an inner diameter of 0.8 mm and a wall thickness of 0.2 mm, embedded inside the phase change material cavity in a serpentine arrangement, with a total length of 2.4 m. The circulating medium inside the tube is a 60:40 volume ratio mixture of deionized water and ethylene glycol, with a freezing point of -25℃ and a boiling point of 110℃. Forced convection cooling is achieved by an external micro centrifugal pump (rated flow rate 120 mL / min, maximum head 0.8 m). The cooling circuit inlet and outlet are connected to aluminum heat dissipation fins on the outer wall of the aircraft fuselage. The fin surface area is 120 cm², and the natural convection heat transfer coefficient is approximately 8 W / (m²·K). Strain release hinge structures are located at the four corners of the connection between the battery pack and the aircraft frame. They adopt a two-degree-of-freedom universal joint design, allowing the battery pack to generate ±3° angular displacement during aircraft vibration without transmitting shear stress to the internal cells. The hinge bushings are made of polyetheretherketone (PEEK) material with a friction coefficient <0.15. The thermal expansion compensation mechanism consists of a bimetallic strip and a sliding guide rail, mounted on the transverse constraint frame of the battery cell array. The bimetallic strip is made of Invar 36 and brass (CuZn37) composite rolled with a thickness ratio of 1:1 and a total thickness of 0.5 mm. When temperature changes cause overall dimensional expansion or contraction, the bimetallic strip compensates for the difference in thermal expansion coefficients. When bending occurs, the sliding guide rail is driven to move laterally, automatically adjusting the lateral constraint force. The fluctuation range of the target constraint force is controlled within ±0.1MPa to avoid interface cracking caused by the accumulation of thermal stress.

[0032] The multi-source state sensing network covers the entire battery system, including a temperature gradient sensor array, a triaxial vibration accelerometer, a barometric altimeter, a cell voltage / current sampling unit, and an insulation resistance monitoring circuit. The temperature gradient sensor array consists of 24 K-type thermocouple nodes, arranged on the surface of 8 cells (3 points per cell), inside the phase change material cavity (6 points), and at the inlet and outlet of the cooling circuit (2 points). The sampling accuracy is ±0.5℃, and the sampling period is 100ms, used to construct a three-dimensional thermal field distribution model. The triaxial vibration accelerometer, model ADXL357, is fixed at the geometric center of the battery pack. It has a range of ±10g and a bandwidth of 1kHz. It collects the vibration frequency and amplitude of the body in the X, Y, and Z directions in real time, and the data is transmitted through the I²C interface. The barometric altimeter, model MS5611, is integrated into the aircraft's main control system. It has a measurement range of 300-1100 hPa and an altitude resolution of 0.1 m. Its output signal is synchronized to the edge intelligent control unit via the CAN bus to calculate the ambient temperature (according to the international standard atmospheric ISA model) and atmospheric density corresponding to the current flight altitude. The cell voltage / current sampling unit uses an isolated differential amplifier circuit INA149 with a common-mode rejection ratio >100dB. It samples the terminal voltage (range 0-4.5V, accuracy ±1mV) and branch current (range 0-30A, accuracy ±0.1A) of each solid-state cell at millisecond-level intervals of 10ms. The insulation resistance monitoring circuit continuously monitors the insulation status between the battery pack casing (grounded) and the internal high-voltage positive busbar using a DC injection method. The injection voltage is 50VDC, and the measurement range is 0.1MΩ to 10GΩ. When the insulation resistance falls below the safety threshold of 100MΩ, the protection mechanism is immediately triggered, cutting off the high-voltage output.

[0033] The edge intelligent control unit is the core processing module. Its hardware platform is the STM32H743 embedded microcontroller based on the ARM Cortex-M7 core, with a main frequency of 480MHz. It has a built-in Trusted Execution Environment (TEE) TrustZone. All sensitive data processing (including interface impedance data, insulation status, and flight control commands) is completed in this secure area to prevent malicious tampering. This unit is interconnected with the multi-source state awareness network, the interface adaptive control module and the main flight control system of the aircraft via a high-speed CANFD bus (5Mbps baud rate), and communicates with the local monitoring circuit of each solid-state cell via the SPI interface (20MHz clock frequency). Internally, it stores a pre-trained interface degradation prediction model. This model is built based on the correlation data of vibration spectrum (0-500Hz), temperature gradient (ΔTmax), current distribution non-uniformity (Jstd / Jmean), and interface impedance Rct collected from 100 historical flight missions. It adopts a lightweight decision tree algorithm (depth ≤8, number of nodes ≤128), with inference latency <2ms and accuracy ≥93%. Before each flight mission is launched, the edge intelligent control unit first reads the flight path altitude profile (including ascent, cruise, and descent phases), estimated flight time (maximum 120 minutes), and maximum load power (peak 3.5kW) from the flight plan. Combined with the current ambient temperature (provided by ground weather stations or airborne sensors), it calls the thermal-power management parameter library to generate an initial control strategy, including the initial speed of the cooling pump (30%-100% PWM duty cycle), the basic excitation frequency of the piezoelectric actuator (20-30kHz), and the upper limit of the discharge current of each cell (weighted according to SOC). During flight, it integrates multi-source sensing data in real time and performs a state assessment every 100 milliseconds: if the triaxial vibration accelerometer detects a high-frequency impact event (Z-axis acceleration > 5g and frequency > 200Hz lasting for 100ms), it immediately increases the activation sensitivity of the piezoelectric actuator and tightens the current density abnormal threshold from ±15% to ±10%. If the temperature gradient sensor shows the formation of local hot spots (temperature difference between two adjacent points > 8℃), the flow distribution of the cooling loop in the corresponding area is increased through the proportional-integral-derivative (PID) controller, and the target temperature difference is controlled at ≤ 5℃. If the interface impedance monitoring circuit identifies that the Rct of a certain cell is higher than the convergence judgment condition three times consecutively (Rct > 1.5 × ... ,in If the discharge rate is dynamically reduced to 0.5C and a micro-vibration repair program with a frequency of 25kHz and an amplitude of 120Vpp is initiated, which lasts for 30 seconds, the initial value of the new battery cell is used. When the aircraft enters the hovering or low-speed cruise phase (power requirement < 1kW), the system utilizes this low-power window to perform a complete AC impedance spectrum scan and update the interface health status database. After the mission is completed, the edge intelligent control unit generates a battery health report for this flight, including the cumulative number of interface repairs, coordinates of the maximum heat load area, insulation performance change trend (expressed as daily decay rate), and estimated remaining available capacity, which is uploaded to the ground maintenance terminal via the CAN bus.

[0034] The communication and power interface module includes dual redundant CAN communication channels, high-voltage DC output terminals, emergency power-off relays, and an electromagnetic shielding housing. The dual redundant CAN communication channels use independent physical lines and protocol stacks. One channel is the primary channel (CAN1) connected to the flight control system, and the other is the backup channel (CAN2) connected to the ground monitoring terminal. Fault switching between the two is achieved through a hardware watchdog chip MAX6816, with a switching time of <10ms. The high-voltage DC output terminal adopts MIL-DTL-38999SeriesIII aerospace-grade connectors with a rated voltage of 500VDC and a rated current of 100A. It integrates a bimetallic thermal fuse (operating temperature 120℃) and a fast-blow overcurrent fuse (rated current 120A, I²t=500A²s). The power supply is automatically cut off when the output current exceeds 110A for 500ms or the terminal temperature rises abnormally to 115℃. The emergency power-off relay has a contact load capacity of 200A / 600VDC. It is dually controlled by the aircraft's main control system and the edge intelligent control unit through an independent optocoupler drive circuit. If either system issues an emergency stop command, all battery cell outputs can be disconnected within 8ms. The electromagnetic shielding shell is made of a three-layer composite structure: the outer layer is a 0.1mm thick copper foil (shielding effectiveness ≥80dB@1GHz), the middle layer is a 0.3mm thick permalloy (μr>50,000), and the inner layer is a 1mm thick conductive rubber (volume resistivity<0.01Ω·cm). It completely encloses the entire battery system, effectively suppressing the influence of external radio frequency interference on the internal weak electrical signals and preventing electromagnetic radiation from the battery from interfering with the flight control system.

[0035] The solid-state battery array adopts a modular design, with each module containing eight solid-state individual cells (nominal voltage 3.7V, capacity 5.0Ah). The modules are physically and electrically connected through quick-release mechanical latches (compliant with ISO11843 standard) and waterproof electrical connectors (IP67 rating). The module shell is made of carbon fiber reinforced polyetherimide (CF / PEI) composite material with a density of 1.4 g / cm³ and a tensile strength of ≥200 MPa. It has four standard M4 mounting holes with a spacing of 50 mm × 50 mm, which facilitates quick replacement on different models of aircraft. Each module integrates an independent local BMS, with hardware based on the TIBQ76952 chip. It is responsible for the passive equalization charging of the cells within the module (equalization current 100mA), temperature monitoring (8-channel thermistor input), and fault reporting (overvoltage, undervoltage, overtemperature, communication loss). The local BMS and the edge intelligent control unit exchange data via power line carrier communication (PLC) at a carrier frequency of 131kHz and a data rate of 9.6kbps. No additional wiring is required, saving approximately 150g per module.

[0036] Furthermore, the dynamic power scheduling strategy executed by the edge intelligent control unit is implemented based on the following mathematical model. Total available power of the system Determined by the following formula: , in, For the number of online battery cells, For the first The maximum allowable discharge current for each cell. Its terminal voltage, The upper limit of power under thermal constraints, This represents the upper limit of power under mechanical integrity constraints.

[0037] Thermally confined power From local temperature Determined by cooling capacity: , in, The comprehensive heat dissipation coefficient (unit: W / ℃) ranges from 8 to 15 W / ℃ and is dynamically adjusted according to the cooling pump speed. The upper limit for safe temperature is set at 60℃.

[0038] Mechanical integrity constraint power With interface impedance and vibration intensity Related: , in, The nominal power is 3.2kW. , , This is the root mean square value of the triaxial vibration acceleration (unit: m / s²).

[0039] Maximum discharge current Modulated by both SOC and state of health (SOH): , in, (Corresponding to 3C), function and Defined as: , in, For the first The state of charge of the battery cell, Its health status (expressed as capacity retention rate).

[0040] All parameters in the above formula are calculated in real time in the embedded software of the edge intelligent control unit, and the power distribution command is updated every 100ms to ensure that the system maximizes energy output within the safety boundary.

[0041] In summary, this invention maintains the physical contact integrity of the solid electrode / electrolyte interface under dynamic operating conditions of an aircraft through the synergistic effect of piezoelectric actuators and elastic support grids, avoiding a sudden increase in interface impedance caused by microcrack propagation; and utilizes a composite thermal management mechanism of phase change materials and microchannel liquid cooling to achieve uniformity of the internal thermal field of the battery pack without external forced air cooling, thus suppressing thermal stress-induced interface debonding. It achieves early identification and local isolation of interface degradation based on multi-source sensing fusion, preventing single-point failure from evolving into system-level power interruption; it ensures that the battery system can still output rated power stably under the combined disturbance of high-frequency vibration of the body and sudden change of atmospheric temperature; and it improves the maintainability and task continuity of the system through modular quick-swap structure and redundant communication design. Lightweight packaging and intelligent power scheduling strategies effectively balance the contradiction between safety redundancy and energy density, enabling solid-state lithium battery systems to meet aviation safety standards while supporting low-altitude flying robots to complete long-endurance operations.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-safety, long-endurance solid-state lithium battery system for low-altitude flight robots, characterized in that, include: Solid-state battery cell array is composed of multiple solid-state individual cells connected in series and parallel. Each solid-state individual cell includes a positive electrode composite layer, a solid electrolyte layer, a negative electrode composite layer and current collectors on both sides. The positive electrode / electrolyte interface is provided with a buffer layer, and each cell is encapsulated in a housing with an elastic support grid inside the housing. An interface adaptive control module is embedded in the housing of each cell package. It includes a piezoelectric actuator array, a local current density sensor and a real-time interface impedance monitoring circuit. The piezoelectric actuator drive end is coupled to the elastic support grid and applies high-frequency micro-amplitude vibration in response to abnormal interface impedance or current density signals to repair interface debonding. The distributed coupling management module, arranged around the solid-state battery cell array, includes a phase change material filling cavity, a microchannel liquid cooling circuit embedded therein, a strain release hinge structure set at the connection between the battery pack and the aircraft frame, and a thermal expansion compensation mechanism installed on the lateral constraint frame of the battery cell array. The multi-source state sensing network includes a temperature gradient sensor array, a triaxial vibration accelerometer, a barometric altimeter, a cell voltage / current sampling unit, and an insulation resistance monitoring circuit. The edge intelligent control unit has a built-in interface degradation prediction model trained based on historical flight data, which initiates the cell isolation procedure when irreversible interface degradation is detected. The communication and power interface module includes dual redundant CAN communication channels, a high-voltage DC output terminal with overcurrent and overtemperature protection, and an emergency power-off relay controlled by both the flight control system and the edge intelligent control unit.

2. The solid-state lithium battery system according to claim 1, characterized in that, In the solid-state single cell, the positive electrode composite layer is formed by mixing and pressing high-voltage nickel manganese cobalt oxide active material, conductive carbon network and ion-conductive polymer binder; the solid electrolyte layer is a dense sintered garnet-type oxide ceramic film; and the negative electrode composite layer is formed by combining pre-lithiated silicon carbon composite material and flexible ion-conductive polymer matrix. Each functional layer is bonded at the interface through a low-temperature co-firing process, and the buffer layer at the positive electrode / electrolyte interface is an alumina layer formed by atomic layer deposition.

3. The solid-state lithium battery system according to claim 1, characterized in that, The elastic support mesh is woven from shape memory alloy wires.

4. The solid-state lithium battery system according to claim 1, characterized in that, The interface impedance monitoring circuit periodically injects a broadband excitation signal during the non-power output period of the aircraft and analyzes the Nyquist diagram to extract the interface charge transfer resistance and diffusion impedance parameters. When the current density in the micro-area deviates from the reference value by more than a preset threshold, the piezoelectric actuator at the corresponding position is triggered to work.

5. The solid-state lithium battery system according to claim 1, characterized in that, The phase change material filling cavity is filled with a paraffin-based composite phase change material. The microchannel liquid cooling circuit is composed of flexible silicone tubes, with the internal circulation medium being a mixed solution of deionized water and ethylene glycol, and is connected to the heat dissipation fins on the outer wall of the machine. The thermal expansion compensation mechanism consists of a bimetallic strip and a sliding guide rail, which automatically adjusts the lateral constraint force according to temperature changes to avoid the accumulation of thermal stress.

6. The solid-state lithium battery system according to claim 1, characterized in that, In the multi-source state perception network, a temperature gradient sensor array is used to construct a three-dimensional thermal field distribution model, and a triaxial vibration accelerometer is fixed at the center of the battery pack to collect the vibration spectrum of the machine body.

7. The solid-state lithium battery system according to claim 1, characterized in that, The interface degradation prediction model stored inside the edge intelligent control unit adopts a lightweight decision tree algorithm. The inputs include vibration spectrum, temperature gradient, current distribution non-uniformity and interface impedance parameters, and the output is a cell health status assessment. The total available power of the system is dynamically determined by the following formula: , in Related to local temperature and cooling capacity, It exhibits an exponential decay relationship with interface impedance and vibration intensity. It is modulated by both SOC and SOH.

8. The solid-state lithium battery system according to claim 1, characterized in that, In the communication and power interface module, the dual redundant CAN channels achieve fault switching through a hardware watchdog. The high-voltage DC output terminal integrates a temperature fuse and an overcurrent fuse.

9. A dynamic power scheduling and interface maintenance method for a high-safety, long-endurance solid-state lithium battery for low-altitude flight robots, applicable to the solid-state lithium battery system described in any one of claims 1-8, characterized in that, Includes the following steps: Before the flight mission is launched, an initial set of thermal-mechanical management parameters is generated based on the flight path altitude profile, estimated flight time, load requirements and ambient temperature. During flight, multi-source sensing data is integrated to perform status assessment: if high-frequency impact vibration is detected, the activation sensitivity of the piezoelectric actuator is increased; if local hot spots are identified, the cooling flow rate in the corresponding area is increased; if the interface impedance is found to be continuously exceeding the standard and accompanied by abnormal current, the cell discharge rate is reduced and micro-vibration repair is initiated. Perform a full AC impedance spectroscopy scan during the low-power window to update the interface health database; When it is determined that a certain battery cell has undergone irreversible degradation, its series circuit is immediately cut off and the redundant branch is activated. At the same time, a power degradation warning is sent to the flight control system. After the task is completed, a battery health report is generated, which includes the cumulative number of repairs, the area of ​​maximum heat load, the trend of insulation performance, and the remaining capacity estimate.

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