44 results about "Polarization impedance" patented technology

The invention discloses a battery pack equalization control method and system based on multidimensional state mapping, and the method comprises the steps: obtaining terminal voltage data, working current data and surface temperature data of each single battery in a target battery pack; calculating an ohm internal resistance value and a polarization impedance value of each single battery; calculating an impedance growth rate; according to the impedance growth rate and the surface temperature data, a health state value is determined, and an aging weighting coefficient is determined; determining a polarization safety coefficient of each single battery based on the polarization impedance value; calculating a state-of-charge value of each single battery in the target battery pack, and determining a balance demand deviation degree; determining a basic equalization duty ratio of each single battery according to the equalization demand deviation degree; correcting the basic balance duty ratio to generate a target pulse width modulation duty ratio; and according to the target pulse width modulation duty ratio, controlling equalization circuits connected to the two ends of each single battery to be switched on. The battery pack equalization control efficiency is improved.

The invention provides a composite positive electrode material and a preparation method and application thereof, the composite positive electrode material comprises a matrix and a carbon coating layer on the surface of the matrix, and the matrix comprises a porous LMFP material; the porous LMFP material comprises doped metal elements, and holes of the porous LMFP material comprise a lithium supplement agent. Doping elements in the composite positive electrode material can improve the stability of a crystal structure and reduce high-temperature storage and cyclic gas production, and the lithium supplement agent in the porous LMFP material can prolong the cycle life of the material and can be decomposed to form pores again after first-time charging, so that an electrolyte can enter the interior of material particles, and the service life of the material is prolonged. And the carbon coating layer can improve the conductivity of the material and reduce the polarization impedance of the material, and meanwhile, the processing problems that residual alkali on the surface of the lithium supplementing agent reacts with a glue solution, so that slurry is gelled and the like can be avoided.

The invention discloses a load control method and system for mobile energy storage equipment, a medium and a product, and the method comprises the steps: obtaining the motion state data and environment state data of target mobile energy storage equipment; performing second-order differential operation on the real-time speed to obtain a jerk value; generating a power demand impact sequence; based on the real-time polarization impedance and the real-time open-circuit voltage, calculating a maximum pulse discharge power threshold value under the condition that a preset under-voltage protection threshold value is not triggered; when the maximum power demand value in the power demand impact sequence is greater than the maximum pulse discharge power threshold, determining that the target mobile energy storage equipment has a power supply drop risk in a preset load prediction time window; calculating an energy gap prediction sequence based on waveform integration of the power demand impact sequence; and generating a feed-forward compensation instruction based on the energy gap prediction sequence, and controlling an auxiliary power conversion unit in the target mobile energy storage equipment to execute the feed-forward compensation instruction. And the accuracy of load control is improved.

According to the valve-regulated lead-acid storage battery state-of-health assessment method and system provided by the invention, the characteristic frequency points which are not sensitive to the change of the charge state but sensitive to the aging degree in the relaxation time distribution map of the battery are innovatively screened, and the multi-parameter fusion assessment model based on the polarization impedance, the ohmic internal resistance and the residual capacity is established; the defect that a single capacity index cannot reflect a historical aging path of the battery is overcome, the future attenuation trend of the battery can be predicted while the current health state is accurately quantified, the influence of charge state fluctuation on health assessment is effectively avoided based on a dual-stability screening mechanism of a characteristic frequency point, the assessment reliability under a complex working condition is improved, and the assessment accuracy is improved. The full-band impedance test is simplified into specific target frequency point measurement, so that the detection time is greatly shortened, and the on-site rapid evaluation requirement is met.

The invention belongs to the technical field of lithium battery materials, and particularly discloses a porous carbon negative electrode material for a lithium ion battery and a preparation method of the porous carbon negative electrode material. Firstly, a copolymer is prepared through staged polymerization of a functional monomer and a chain transfer agent; secondly, taking nano molybdenum trioxide and zinc acetate dihydrate as raw materials, and performing ball milling and roasting to form a core-shell template; then, mixing and sieving the copolymer, the core-shell template, sodium chloride and the polymethyl methacrylate microspheres to obtain a precursor; and finally, carrying out multi-stage heating carbonization and post-treatment on the precursor to obtain the porous carbon negative electrode material. The obtained negative electrode material has a hierarchical porous structure and a high specific surface area, synergistic doping of multiple elements such as nitrogen, phosphorus and molybdenum is realized, rapid transmission and efficient storage of lithium ions are effectively promoted, the rate capability and cycling stability of a battery are remarkably improved, polarization impedance is reduced, and meanwhile, the electronic conductivity and interface stability of the material are further optimized; excellent comprehensive electrochemical performance is shown in the application of a high-energy-density lithium ion battery.

This invention relates to a medium-temperature solid oxide fuel cell cathode material and its preparation method. The invention employs a sol-gel method to synthesize perovskite oxide Pr 0.1 Ba 0.9 Co 0.8 Zr 0.1 Y 0.1 O 3‑δ The material contains PrBaCo2O with a double perovskite structure. 5+δ BaCo with single perovskite structure 0.8 Zr 0.1 Y 0.1 O 3‑δ Two phases. Multiphase Pr 0.1 Ba 0.9 Co 0.8 Zr 0.1 Y 0.1 O 3‑δ The sample achieved a conductivity of 100 S / cm within the operating temperature range of a mid-temperature solid oxide fuel cell. ‑1 At 700℃, the polarization impedance is 0.06 Ωcm. 2 This meets the requirements for cathode materials in solid oxide fuel cells. The electrolyte-supported single cell achieved a maximum power density of 710 mW / cm³ at 800℃. ‑2 The single cell underwent continuous and stable discharge at a constant current for 200 hours without performance degradation, demonstrating excellent output performance stability. In summary, perovskite oxide Pr 0.1 Ba 0.9 Co 0.8 Zr 0.1 Y 0.1 O 3‑δ It is a potential cathode material for intermediate-temperature solid oxide fuel cells.

The invention discloses an application of a sea urchin-shaped spinel electrode material in a solid oxide fuel cell (SOFC), and the SOFC oxygen electrode material is sea urchin-shaped NiCo2O4 spinel and is prepared by a hydrothermal method. The sea-urchin-shaped spinel is self-assembled to the surface of the YSZ electrolyte through a current polarization induction method, the sea-urchin-shaped spinel electrode can maintain a good nano structure and a high specific surface area without a high-temperature sintering process, an SOFC based on the sea-urchin-shaped spinel oxygen electrode obtains excellent electrochemical performance, and at the working temperature of 700 DEG C, the electrochemical performance of the SOFC is greatly improved. The maximum output power can reach 2.06 W / cm < 2 >, the ohmic impedance is 0.053 ohm cm < 2 >, the polarization impedance is 0.077 ohm cm < 2 >, and excellent long-term stability is shown.

The invention discloses a composite anode material, an anode, an electrolyte-supported solid oxide fuel cell and a preparation method, and relates to the technical field of cells. The composite anode material comprises a double-perovskite anode material and a metal oxide, the double-perovskite anode material comprises YSZ (Yttrium Stabilized Zirconium) and a double-perovskite material, wherein the double-perovskite material is at least one of PrBaMn2O5, PrBa < 0.5 > Sr < 0.5 > Co < 1.5 > Fe < 0.5 > O5, Sr2CoMoO6, LaBaMn2O5, LaBaCo2O5, Sr2FeMoO6, Ba2FeMoO6, Sr2Fe < 1.5 > Mo < 0.5 > O6 and PrBaFe2O5; and the metal oxide is at least one of NiO, Co3O4 and Fe3O4. The preparation method has the beneficial effects that various metal oxides are mixed into the classic double-perovskite anode material, so that the conductivity of the double-perovskite anode can be improved, the polarization impedance of the double-perovskite anode can be reduced, and finally, the relatively large power density improvement of the cell is realized.

This application provides a sheet-like spinel cobalt ferrite, its preparation method, and its application, belonging to the field of solid oxide battery technology. In this application, a Co source and an Fe source are dissolved in deionized water, citric acid is added and stirred until homogeneous, then heated in a water bath until the solution becomes a reddish-brown transparent gel. The gel is then dried and ground to obtain a first powder. The first powder is then subjected to two CO2 laser-induced oxidation processes in air at a laser power of x to obtain a second powder. Wherein, 4W < x ≤ 10W. Finally, the second powder is washed and dried to obtain a sheet-like spinel cobalt ferrite. Compared with ordinary spinel cobalt ferrite, using the aforementioned sheet-like spinel cobalt ferrite as a cathode material in SOFC can reduce the polarization impedance of the battery by 0.023 Ωcm. 2 The maximum power density increased by 0.38 W / cm². ‑2 This improves the oxygen reduction activity and stability of SOFCs. Furthermore, using CO2 laser-induced methods simplifies the preparation process, reduces time costs, and increases production efficiency.

The application relates to the field of power supply circuits and electric energy storage systems, and discloses a full-life-cycle adaptive optimization scheduling method for an energy storage system of a micro-grid cluster, which comprises the following steps: acquiring polarization impedance data of each energy storage branch representing electrode interface charge transfer resistance and an operating state, and decomposing bus net load power into a transient high-frequency sequence and a steady-state low-frequency sequence; distributing high-frequency fluctuation according to the reciprocal of the polarization impedance, adjusting the virtual impedance gain of a power conversion unit control loop to make the output current change rate lower than the physical boundary of ion diffusion rate; and introducing carbon emission intensity weight and loss cost function to correct the power limit value. The application establishes the physical correlation between the battery kinetics and the power fluctuation frequency, smoothes the current waveform by using the virtual impedance adjustment technology, suppresses the concentration polarization and lithium precipitation phenomenon of the electrode interface, and essentially prolongs the service life of the energy storage system.

Methods and systems for controlling and monitoring a vehicle battery pack using a battery impedance model are provided. An electrically powered vehicle (EV) includes a battery pack, one or more sensors, and a vehicle controller. The battery pack includes a plurality of battery cells and is operable to provide at least a portion of propulsion power. The vehicle controller is configured to charge and discharge the battery pack according to a power limit defined by an output of a battery impedance model. The battery impedance model associates a battery impedance value with a frequency-dependent polarized impedance value representative of a diffusion state of the battery cell, and receives a parameter indicative of a measurement of the frequency-dependent polarized impedance value of the battery pack from the one or more sensors.

This invention provides a one-dimensional surface-shared oxide air electrode material, its preparation method, and its application, belonging to the technical field of air electrode materials. The novel one-dimensional surface-shared oxide air electrode material provided by this invention, which is non-stoichiometric, is A5B5O. 14 Type oxide, with the chemical formula Ba 5‑x Co 2.85 Fe 1.9 Ni 0.25 O 14‑δ Where 0 ≤ x ≤ 0.8. This invention modulates the oxygen vacancy concentration by changing the stoichiometric ratio of Ba at the A-site of the oxide, thereby improving its electrochemical performance in proton-conducting ceramic batteries. In Example 3 of this invention, Ba with x = 0.5... 4.5 Co 2.85 Fe 1.9 Ni 0.25 O 14‑δ When applied to proton-conducting ceramic batteries, it exhibits the highest measured electrochemical performance; at 700℃, in fuel cell mode, the measured polarization impedance is only 0.041 Ω·cm. 2 Its maximum power density reaches 2.101 W·cm³. ‑2 In electrolytic cell mode, after introducing humid air to the air electrode side, the current density reached 5.080 A·cm⁻¹ at an electrolytic voltage of 1.3V. ‑2 .

An electrified vehicle (EV) includes a battery pack, one or more sensors, and a vehicle controller. The battery pack includes a plurality of battery cells and is operable to provide at least a portion of motive power. The vehicle controller is configured to charge and discharge the battery pack according to power limits defined by an output of a battery impedance model. The battery impedance model maps battery impedance values ​​to frequency-dependent polarization impedance values ​​representing diffusion states of the battery cells and receives measured parameters from the one or more sensors indicative of the frequency-dependent polarization impedance values ​​of the battery pack.

The invention discloses a solid electrolyte with a three-period minimum curved surface structure, a solid oxide fuel cell and a preparation method of the solid electrolyte and the solid oxide fuel cell, the solid electrolyte has the three-period minimum curved surface structure, and the three-period minimum curved surface structure is a P-cell structure, an IWP structure or a Neovius structure. According to the solid electrolyte provided by the invention, gas can more conveniently flow into the structure to generate electrochemical reaction, so that the interface contact area of the electrode-electrolyte can be greatly increased, more three-phase boundaries (TPB) can be provided, oxygen reduction (cathode) and fuel oxidation (anode) reactions can be promoted, the electrochemical activity per unit area is improved, and the polarization impedance is reduced.

The invention belongs to the technical field of electrochemical materials, and particularly relates to an anti-Cr poisoning composite current collecting layer for a solid oxide fuel cell as well as a preparation method and application of the anti-Cr poisoning composite current collecting layer. The Cr poisoning resistant composite current collecting layer is a composite current collecting layer constructed by adopting two perovskite materials LCN and LSCN, and the problem of cathode failure caused by volatilization of metal connector Cr is successfully solved by combining the physical barrier characteristic of strontium-free LCN and the chemical capture characteristic of strontium-containing LSCN. The invention aims at an SOFC system using an iron-based alloy as a connector, and aims at solving the technical problem that the catalytic activity of a cathode is attenuated due to chromium species volatilized by a metal connector in a high-temperature oxygen-enriched environment, so that the long-term operation stability of a cell stack is remarkably improved, and the service life of the cell stack is remarkably prolonged. According to the invention, through specific material combination and layered structure design, the contradiction that a single current collecting layer is difficult to give consideration to Cr volatilization blocking and low contact resistance maintaining is solved, and the polarization impedance growth rate of the cell is significantly reduced.

A lithium ion battery polarization anti-energy model and safety state determination method comprises the following steps: obtaining an equivalent circuit model corresponding to a measured electrochemical impedance spectrum through equivalent circuit modeling, embedding the equivalent circuit model into a vehicle-mounted battery management system, and carrying out battery model parameter identification to obtain model parameter values in real time; meanwhile, the electrochemical impedance spectrum of the battery in the actual use process is calculated by utilizing the parameter values, and polarization energy resistance modeling is carried out by taking the area enveloped by the polarization impedance and the coordinate axis of the battery in the actual use process as polarization energy resistance to obtain the polarization energy resistance of the battery at each moment in the use process; and defining the ratio of the polarization energy resistance at each moment to the polarization energy resistance of the battery in a brand new state as a polarization energy resistance state, and judging the safety state of the battery by using the polarization energy resistance state. From the perspective of the reactance of the battery, the invention provides a brand-new battery safety state judgment method, and a new thought is provided for realizing the safety management of the battery.

The present application relates to the technical field of sodium-ion battery health management, in particular to a sodium-ion battery SOC estimation method and system for a DC screen. First, the ohmic impedance and polarization impedance of each battery are obtained, and the reference ohmic impedance and reference polarization impedance are extracted. Further, the capacity loss index is obtained according to the difference between the ohmic impedance of each battery and the reference ohmic impedance, combined with the difference between the polarization impedance and the reference polarization impedance. Further, the historical minimum polarization reference of the battery pack is maintained, and the correction loss value is obtained according to the difference between the current reference polarization impedance and the historical minimum polarization reference, combined with the capacity loss index. Further, the correction loss value is converted into a single battery charge loss amount. Finally, based on the single battery charge loss amount, the system effective SOC of the battery pack is determined according to the series short board effect of the battery pack, and reliable basis is provided for operation and maintenance personnel.

The invention discloses a low-impedance porous support type SOFC (Solid Oxide Fuel Cell) electric pile and a preparation method thereof, and belongs to the technical field of solid oxide fuel cells. The electric pile comprises an anode porous supporting body, an electrode active layer, an electrolyte layer and an interconnection material, and by adopting a porous supporting electrode structure and combining a directional micro-channel design, the ohmic impedance is remarkably reduced by 30%-40%, and the polarization impedance is remarkably reduced by 20%-30%. An electrode and electrolyte interface is optimized by adopting the combination of processes such as an impregnation method, plasma spraying and co-sintering, and the interface resistance is reduced by 25-30% by introducing the gadolinium-doped cerium oxide transition layer, so that the electrochemical performance and long-term operation stability of a galvanic pile are improved. Under the operation condition of 700-800 DEG C, the output power density of the electric pile reaches 1.5 W / cm < 2 >-2.0 W / cm < 2 > which is improved by 30%-50% compared with that of a traditional electric pile, and the thermal cycling stability and the long-term operation stability are also remarkably improved.

The application belongs to the technical field of lithium battery materials, and specifically discloses a kind of porous carbon negative electrode material for lithium ion battery and its preparation method. First, a copolymer is prepared by stage polymerization of functional monomers and chain transfer agent; second, a core-shell template is formed by ball milling and calcination using nano-molybdenum trioxide and zinc acetate dihydrate as raw materials; then, the copolymer, core-shell template, sodium chloride and polymethyl methacrylate microspheres are mixed and sieved to obtain a precursor; finally, the precursor is subjected to multi-stage temperature carbonization and post-processing to obtain a porous carbon negative electrode material. The obtained negative electrode material has a hierarchical porous structure and a high specific surface area, and realizes the synergistic doping of multiple elements such as nitrogen, phosphorus and molybdenum, effectively promoting the rapid transmission and efficient storage of lithium ions, significantly improving the rate performance and cycle stability of the battery, reducing the polarization impedance, and further optimizing the electronic conductivity and interface stability of the material, which exhibits excellent comprehensive electrochemical performance in high-energy-density lithium ion battery applications.

The invention provides a high-entropy perovskite-based composite electrode material, a preparation method of the high-entropy perovskite-based composite electrode material, electrode slurry, an electrode and a solid oxide battery. The chemical formula of the high-entropy perovskite-based composite electrode material is (A < 1-x > Ce < x >) < y > BO < 3-delta >, a is selected from a combination of four or more than five of alkaline earth metal elements and rare earth elements, and A is not Ce; b is selected from one or a combination of more than two of transition metal elements; 0 < x < = 1, 0.5 < = y < 1, and delta is oxygen vacancy content. The high-entropy perovskite-based composite electrode material disclosed by the invention has excellent catalytic activity, shows excellent stability in an air atmosphere and in a severe actual working environment of a battery containing water, Cr and the like, and has relatively low polarization impedance.

This invention relates to the field of intelligent monitoring technology, specifically a monitoring and intervention system based on wearable electromyography (EMG) sensing. The system includes: an impedance compensation acquisition module that applies a variable capacitance bias voltage to acquire discrete EMG parameters; a trajectory vector reconstruction module that generates a coordinate matrix and calculates the cosine of the tangent angle; a spasm identification and judgment module that calculates the output signal when the dispersion exceeds the limit; a residual tension mapping module that generates an attenuation slope based on the over-limit parameters; and a stimulation waveform modulation module that generates an intervention waveform in combination with a safety benchmark. In this invention, high-fidelity discrete signals are acquired by dynamically compensating for the polarization impedance fluctuations of the skin contact surface, mapping the one-dimensional potential of the time sequence to a multi-dimensional phase space and calculating the tangent vector dispersion, accurately capturing the nonlinear abnormal variation characteristics hidden in muscle spasms, dynamically converting the attenuation rate based on the tension difference and setting a safety limit benchmark in combination with the joint range of motion, outputting an intervention waveform adapted to the current tension level, and providing truncation protection when the limit is exceeded.

The invention provides a collaborative test device and method for polarization internal resistance and electrochemical impedance spectroscopy of a storage battery, and relates to the technical field of battery management, and the device comprises a polarization internal resistance test unit, an EIS test unit, a sampling unit and a central processing unit. The polarization internal resistance test unit is used for carrying out polarization internal resistance test control on the storage battery and controlling the sampling unit to carry out sampling; and the EIS test unit is used for carrying out electrochemical impedance spectroscopy test control on the storage battery and controlling the sampling unit to carry out sampling. Polarization internal resistance testing and electrochemical impedance spectroscopy testing of the storage battery are integrated in the same testing device, a collaborative testing framework is constructed, collaborative analysis of the polarization internal resistance and polarization impedance of the storage battery can be obtained through one device, combination of the polarization internal resistance reflecting ohmic polarization and EIS data reflecting electrochemical kinetics is achieved, and the testing accuracy is improved. The state of the storage battery is comprehensively described, the problem of large deviation of single alternating-current impedance evaluation capacity / SOH is solved, and the accuracy and the detection speed of capacity and SOH evaluation results are improved.

The application belongs to the technical field of new materials, and discloses a porous electrode material, an electrode and a preparation method thereof and a solid oxide electrolysis cell. 1.5 Mo 0.5‑x W x O6- δ wherein x represents a molar fraction, and the value range of x is 0 1.5 Mo 0.5 O6 perovskite material, a W-doped Mo is used to replace part of Mo, and a porous electrode material is designed by using the higher valence and electronegativity of W relative to Fe and Mo, and the smaller ionic radius of W relative to Mo. The electrode material not only has high CO2 adsorption, but also has high temperature stability and high catalytic activity. When the electrode material is applied to the oxide solid electrolysis cell, the current density of SOEC electrolysis CO2 is effectively improved, and the polarization resistance of the material is reduced.

The invention provides an electrode material and application thereof. The expression of the electrode material is PrBa < 0.8 > Ca < 0.2-x > Rb < x > Co < 2 > O < 5 + delta >, wherein 0 < x < = 0.15, and delta is oxygen vacancy content. The electrode material provided by the invention is an Rb < + > doped double perovskite material, and has good stability, relatively low polarization impedance and relatively high ORR / OER activity. The invention also provides a preparation method of the double perovskite material and an anode-supported reversible proton ceramic electrochemical cell containing the double perovskite material. The anode-supported reversible proton ceramic electrochemical cell provided by the invention has good stability, electrocatalytic activity and electrochemical performance, and has important application in the field of hydrogen fuel cells.

The invention relates to the technical field of energy optimization scheduling, and particularly provides a wind, light and heat storage multi-energy system optimization scheduling method based on self-adaptive dynamic programming. The core of the method is to reversely utilize the'heat conduction lag-morphological difference 'coupling effect of rotor thermal stress: firstly, completing thermal risk trend quantification by morphological deviation of node virtual temperature and a reference sequence; a risk adjustment coefficient, battery polarization impedance and a charge constraint term are extracted under a power adjustment working condition, and a battery suppression weight is calculated by means of normalization and feature fusion; the system automatically distributes scheduling instructions to batteries and photo-thermal power stations by embedding dynamic weights into a quadratic programming objective function. According to the method, radial temperature field deduction-thermal expansion stress prediction-form deviation quantification is taken as a judgment basis, a blind area of a single-point threshold value to heat conduction lag is eliminated, the precision and response speed under second-level rolling optimization are ensured, and collaborative optimization of rotor thermal shock suppression, battery aging delay and unit climbing cost is realized.

The invention relates to a surface-reconstructed oxygen electrode material, a preparation method thereof and a proton ceramic electrolytic tank, and belongs to the technical field of solid oxide fuel. After in-situ treatment, the nano spinel is uniformly distributed on the surface of the parent-phase perovskite type oxide, so that more active sites can be provided for exchange and transmission of oxygen, meanwhile, desorption of oxygen is promoted, and the reaction is accelerated. After in-situ treatment, the polarization impedance of the oxygen electrode is reduced, and the electrochemical activity is obviously improved.

The invention discloses a high-catalytic-activity air electrode, a preparation method thereof and a solid oxide fuel cell, and relates to the technical field of cells. The preparation method of the air electrode comprises the following steps: synthesizing a CaFe0. 5Al0. 25Cu0. 25O3-delta material, wherein delta is more than or equal to 0 and less than 1; the method comprises the following steps: loading a CaFe < 0.5 > Al < 0.25 > Cu < 0.25 > O < 3-delta > material on an electrolyte subjected to acid treatment, and sintering at 800 DEG C to 1100 DEG C; and dipping by adopting a mixed salt solution containing Fe (NO3) 3 and Cu (NO3) 2, and continuously sintering at 800-1100 DEG C to obtain the composite material. The invention also provides a solid oxide fuel cell comprising the air electrode. The preparation method has the beneficial effects that the CaFe < 0.5 > Al < 0.25 > Cu < 0.25 > O < 3-delta > material is prepared from low-cost non-noble metal and non-rare earth element raw materials, so that the production cost is reduced; the CaFe < 0.5 > Al < 0.25 > Cu < 0.25 > O < 3-delta > material is subjected to optimization treatment, so that the catalytic activity is improved, and the polarization impedance is reduced.

The invention provides a battery pack capacity dynamic calibration method and system based on multi-time scale model coupling. The method comprises the following steps: collecting data in real time in the charging and discharging process of a battery pack, and identifying the real-time polarization impedance of each single battery on line by using a second-order RC equivalent circuit model; constructing an impedance-capacity coupling model containing a linear attenuation item and an exponential attenuation item taking polarization impedance as an independent variable, and estimating the current maximum available capacity of the single body; the maximum capacity and the impedance voltage drop are comprehensively considered, and the residual discharge time is predicted to lock the short-plate battery; and calculating an inflection point compensation amount according to the impedance change rate of the short-plate battery, and deducting the compensation amount from the theoretical residual capacity of the battery pack to obtain a calibrated actual available capacity. The method can solve the technical problems that the nonlinear capacity diving phenomenon in the later stage of battery aging is difficult to predict in the prior art, and the battery pack is virtually high in electric quantity and suddenly shut down due to the short plate effect caused by single impedance deterioration cannot be effectively handled.

The present invention relates to a low-temperature starting method, device, vehicle and storage medium for a fuel cell stack. The method comprises: determining whether a current fuel cell stack has a low-temperature starting requirement; if the current fuel cell stack has a low-temperature starting requirement, obtaining the current voltage of the current fuel cell stack, and when the current voltage is greater than or equal to a first preset voltage, reducing the cathode stoichiometric ratio of the current fuel cell stack according to a preset reduction strategy, and obtaining the lowest single-chip voltage and coolant temperature of the current fuel cell stack during the process of reducing the cathode stoichiometric ratio; determining the current starting stoichiometric ratio of the current fuel cell stack according to the lowest single-chip voltage and coolant temperature of the current fuel cell stack, and starting the current fuel cell stack according to the current starting stoichiometric ratio. Thus, by precisely coupling the influence of the fuel cell hydrogen permeation current and polarization impedance, the fuel cell stack cathode stoichiometric ratio and fuel cell heat generation are precisely controlled, thereby significantly improving the vehicle's low-temperature starting success rate and increasing the service life of the fuel cell.

The present invention provides a composite cathode material, a preparation method thereof, and a medium and low temperature solid oxide fuel cell, belonging to the technical field of solid oxide fuel cells. First, scandium nitrate, dysprosium nitrate, urea and a solvent are mixed to obtain an impregnating solution; then the cathode matrix material is impregnated in the impregnating solution, and then dried and sintered in sequence to obtain the composite cathode material. By introducing dysprosium and scandium elements into the cathode matrix material, the surface of the cathode matrix material is modified, effectively improving the stability and polarization resistance of the cathode matrix material.