1657 results about "Lithium iron phosphate" patented technology

The invention relates to a method for preparing a lithium iron phosphate / carbon composite material of a lithium ion battery, which belongs to the technical field of lithium ion batteries. The method for preparing the lithium iron phosphate / carbon composite material of the lithium ion battery comprises the following steps of: 1) preparing a suspending graphene-dispersed aqueous solution system, namely, crushing graphite to 1 to 5 microns, adding the crushed graphite into distilled water or purified water, adding 0.1 to 5 percent of surfactant, heating with stirring the mixed solution to 180 to 250 DEG C in a sealing way, performing stirring for 2 to 6 hours and reducing the temperature; 2) crushing lithium iron phosphate to the particle size of 1 to 5 microns, adding the crushed lithium iron phosphate into the distilled water or the purified water, adding with stirring 0.01 to 1 percent of coupling agent, performing uniform stirring, adding the graphene-dispersed aqueous solution, and performing stirring and filtration; and 3) vacuum-drying solid powder obtained by the filtration, and calcinating the dried solid powder for 2 to 12 hours to obtain the graphene-coated lithium iron phosphate cathode material. The method has the advantages of simple process, high material performance, high conductivity, high bulk density, high compacted density and the like.

The invention discloses a multi-modal fusion lithium iron phosphate battery thermal runaway early warning method and system, and the method comprises the steps: collecting multi-source heterogeneous data, such as temperature, voltage, gas concentration and shell strain pressure, in real time through deploying a heterogeneous sensor network, and carrying out the noise reduction and time sequence feature extraction through employing a sub-linear time low-rank approximation algorithm of a Hankel matrix; constructing a cross-modal feature association network by applying a secondary time algorithm of a maximum weight sparse subgraph problem, inputting a fused feature vector into a Bayesian network health degree evaluation model for probabilistic reasoning calculation to obtain a battery health degree score and a thermal runaway risk level, generating a graded early warning signal through multi-level early warning threshold comparison, and performing early warning on the battery health degree score and the thermal runaway risk level. And corresponding prevention and control suggestions are matched. The method solves the technical problems that single physical quantity monitoring is difficult to comprehensively reflect the complex change in the battery and the response delay of a centralized processing architecture causes the early warning lag, and achieves the timely capture and accurate early warning of the early weak characteristics of thermal runaway.

The invention discloses a lithium iron phosphate battery grading active fire control method and system, and the method comprises the steps: collecting multi-mode perception data through deploying a multi-source sensor network and a BMS data interface, and constructing a battery thermal runaway risk assessment model through employing a Lyapunov fixed time stability theory; a hierarchical prevention and control strategy is dynamically generated in combination with a historical case sensitivity scoring mechanism, and linkage response of first-level early warning heat dissipation, second-level aerosol inhibition and third-level perfluorohexanone fire extinguishing is achieved. According to the invention, the problem that the prior art lacks self-adaptability and BMS deep collaboration is solved, the technical transformation from passive response to active prevention and control is realized, and the accuracy and timeliness of thermal runaway early warning are remarkably improved.

The invention discloses a lithium iron phosphate battery anomaly detection method, electronic equipment and a storage medium, and relates to the technical field of battery health management. The method comprises the following steps: acquiring a voltage value and a temperature value of each single battery in a battery cluster every unit time interval, determining a voltage drop rate for any single battery in the battery cluster based on the voltage values of the single battery at the first moment and the last moment in the first unit time, and correcting the voltage drop rate in combination with the temperature value at the last moment. When it is detected that the corrected pressure drop rate is larger than the preset threshold value in the second unit time, the last moment of the second unit time serves as the starting moment, and if the corrected pressure drop rates of all unit time in the first preset time period are all larger than the preset threshold value, the second unit time serves as the starting moment; and if yes, determining an initial voltage entropy value based on the voltage value of each single battery obtained in the last second unit time. According to the invention, the voltage drop rate and the initial voltage entropy value are combined, so that the anomaly detection of the lithium iron phosphate battery is realized.

The invention discloses a secondary battery and an electric device, and belongs to the technical field of secondary batteries. The secondary battery comprises a positive electrode plate, a negative electrode plate and an electrolyte, the positive electrode plate comprises a positive electrode material layer, the positive electrode material layer comprises a positive electrode material, the positive electrode material comprises lithium iron phosphate, the electrolyte comprises a cyclic sulfate compound, the cyclic sulfate compound comprises an electron donating group, and the cyclic sulfate compound comprises an electron donating group. The negative electrode plate comprises a negative electrode material layer, and when the secondary battery is charged to a full charge state, the negative electrode material layer comprises an iron element and LiC6. By regulating and controlling the mass percentage content a% of electron donating groups in the electrolyte, the mass percentage content b% of LiC6 in the negative electrode material layer and the mass content cppm of the iron element in the negative electrode material layer, b / (10a1 / 2 + c) is within a suitable range, active lithium is effectively compensated, and side reactions between the electrolyte and the positive electrode and the negative electrode can be reduced, so that the cycle life and the safety of the battery are both considered.

The invention belongs to the technical field of material recovery, and particularly discloses a regeneration method of a waste lithium iron phosphate battery positive electrode material, a lithium ion battery positive plate prepared from regenerated lithium iron phosphate powder and a lithium ion battery. Waste lithium iron phosphate powder is uniformly mixed with uric acid and a lithium source, and the mixture is subjected to annealing and annealing treatment in an inert atmosphere, so that structure repair and performance upgrading of a failure material are realized. Uric acid serves as a reducing agent and a carbon-nitrogen source at the same time in the process, Fe < 3 + > is effectively reduced through thermal decomposition of the uric acid, anti-position defects are reduced, a uniform nitrogen-doped carbon coating layer is synchronously formed on the surfaces of particles, and the conductivity and the ion diffusion rate of the material are remarkably improved. The method is short in process flow and environment-friendly, and does not need to use strong acid and strong alkali. The regenerated lithium iron phosphate material has excellent electrochemical performance, the capacity retention rate reaches 91.22% after 500 times of circulation under the multiplying power of 0.5 C, the capacity retention rate is far superior to that of a commercial material, and an effective way is provided for high-valued recovery of waste lithium iron phosphate.

The invention belongs to the technical field of resource recycling of waste lithium batteries, and particularly relates to a method for extracting lithium by stripping and coupling organic matter degradation of waste lithium batteries, which comprises the following steps: S1, obtaining a waste lithium iron phosphate positive plate and an organic pollutant aqueous solution; s2, soaking the waste lithium iron phosphate positive plate in an organic acid solution, and stripping to obtain an aluminum foil and a lithium iron phosphate material; s3, adding the lithium iron phosphate material, a complexing agent and an oxidation auxiliary agent into the organic pollutant aqueous solution to obtain a first reaction system, and carrying out a first reaction; after the reaction of the second reaction system is balanced, carrying out solid-liquid separation to obtain filtrate and filter residues, adding a lithium salt precipitator into the filtrate, and filtering to obtain lithium salt and recovering the lithium salt; according to the method, the battery recovery process and the wastewater treatment process are ingeniously coupled, the components of the waste battery material are used as the catalyst, organic pollutants in the environment are degraded, and cooperative treatment of waste and upgrading and recovery of resources are achieved.

The invention relates to the technical field of lithium ion batteries, in particular to a chromium-molybdenum double-doped lithium iron phosphate material as well as a preparation method and application thereof. The preparation method is used for solving the problems of low capacity, low electronic conductivity and poor cycling stability of the existing lithium iron phosphate material. According to the preparation method, chromium-molybdenum is doped into lithium iron phosphate, and the bond energy of a Cr-O bond and a Mo-O bond is stronger than that of a Fe-O bond, so that the dissolution loss of Fe < 2 + > in long-term circulation is reduced, and the battery capacity and the intrinsic electron conductivity of the material are improved; lithium iron phosphate is coated with nitrogen-doped carbon nanotubes, and nitrogen is doped in graphite crystal lattices of the carbon nanotubes, so that additional free electrons are provided, the intrinsic conductivity is improved, the resistance is reduced, the rate capability is improved, and the cycle life is prolonged; the polyaniline coating layer forms a barrier layer on the surface of the lithium iron phosphate particles, so that the cycle performance and the battery capacity are improved; the three components cooperate to improve the capacity, conductivity, rate capability and cycling stability of the material.

The invention provides a lithium ion battery. The lithium ion battery comprises a positive plate and a negative plate, the negative plate comprises a negative electrode material layer, and the negative electrode material layer comprises LiC6; the positive plate comprises a positive material layer; the positive electrode material layer comprises lithium iron phosphate; the particle size of the lithium iron phosphate particles is a [mu] m; the specific surface area of the positive electrode material layer is b m < 2 > / g; a voltage platform exists in a capacity-voltage curve when the lithium ion battery is charged; the corresponding voltage of the voltage platform is 3.9-4.7 V, and the slope of the voltage platform is c; and a relational expression 0.13 < = (a * c * 1000) / b < = 84.2 is satisfied. The particle size of the lithium iron phosphate positive electrode material, the specific surface area of the positive electrode material layer and the slope of a voltage platform in a specific voltage interval are designed to meet a relational expression, so that effective transmission of lithium ions is promoted, the fast charging performance of the battery is improved, side reactions between a positive plate and an electrolyte are reduced under the condition of ensuring sufficient decomposition of a lithium supplementing agent, and the service life of the battery is prolonged. The cycle life of the battery is prolonged.

The invention belongs to the technical field of lithium battery material recovery, and particularly relates to a method for recovering a waste lithium iron phosphate positive electrode material. The method comprises the following steps: (1) grinding and sieving the positive electrode material of the waste lithium iron phosphate battery, mixing with an alkaline solution, stirring and leaching, and carrying out solid-liquid separation to obtain a lithium-rich solution and leaching residues; (2) introducing a saturated sodium carbonate solution into the obtained lithium-rich solution, carrying out heating reaction, filtering, taking a solid phase, and drying to obtain lithium carbonate; and the obtained leaching residues are dried, and ferroferric oxide is obtained. According to the method, the waste lithium iron phosphate battery positive electrode material is leached through the alkaline liquid phase, it can be guaranteed that lithium and iron in waste lithium iron phosphate are separated through a one-step leaching method, and therefore selective lithium extraction is achieved. The whole technological process is convenient to operate, mild in reaction condition and low in energy consumption, does not need to use any acid or oxidant, avoids generation of a large amount of waste liquid and harmful gas, and is high in selective lithium extraction efficiency.

The invention discloses a hybrid energy storage power supply system for diesel engine replacement and an energy management method, and relates to the technical field of hybrid energy storage power supply and management methods. An assembly with the photoelectric conversion efficiency exceeding 23% and a 10KV-level string type inverter are adopted, and a photovoltaic-energy storage combined MPPT control function is integrated; the lithium iron phosphate energy storage system is matched with a bidirectional PCS and an active equalization technology, and is designed according to 1.5 times of daily peak-valley difference and 2 hours of emergency standby power; the diesel generating set group is started in a grading manner according to load gaps, and is matched with a 10KV / 380V intelligent charging unit; the coordination control center realizes two-dimensional prediction and coordinated scheduling based on an LSTM neural network, couples each unit through a 10KV intelligent bus system, divides load priorities, collects meteorological and equipment parameters, and constructs photovoltaic priority consumption, energy storage stabilization fluctuation, diesel generator guarantee emergency, and flexible and adjustable charging operation modes. The method has the advantages that the energy utilization efficiency is improved, the power supply stability is enhanced, the whole-cycle cost is reduced, limited operation and maintenance scenes are adapted, and diversified power supply requirements are met.

A method for preparing a positive electrode material and an energy storage battery are provided. The method includes: preparing an Fe-MOF, including: dispersing a first iron source in a solvent, adding the cyanamide organic ligands into the solvent to perform reflux reaction to obtain a reaction solution, and performing cooling, filtering, and cleaning on the reaction solution to obtain the Fe-MOF; grinding and blending the Fe-MOF with a second iron source, a lithium source, and a phosphorus source to obtain a premix; and performing a sintering treatment on the premix under an atmosphere of an inert gas to obtain a composite lithium iron phosphate positive electrode material. The composite lithium iron phosphate positive electrode material includes lithium iron phosphate particles and carbon nanotubes, the lithium iron phosphate particles are attached to a surface of the carbon nanotubes, and there is iron wrapped by each of the carbon nanotubes.

The invention discloses high-compaction-density modified spherical lithium iron phosphate and a preparation method and application thereof.The preparation method comprises the steps that a composite iron source precursor and modified phenolic resin are compounded to form a spherical inner core, and then the spherical inner core is coated with a lithium-phosphorus mixed layer to construct a core-shell structure; the modified spherical lithium iron phosphate with the characteristics of'spherical core-porous shell 'is prepared by introducing boron nitride nanosheets as a structure-directing agent and a doping source and combining a dynamic gradient sintering process, and the modified phenolic resin is obtained by grafting water-soluble phenolic resin and polyethylene glycol, and the solid content of the modified phenolic resin is greater than or equal to 50%. The modified lithium iron phosphate with the compaction density larger than or equal to 2.55 g / cm < 3 > and the capacity retention ratio larger than 92.0% after 1C circulation 2000 times is prepared, and the technical bottlenecks that doping is not uniform, morphology is out of control and the compaction density is low in a traditional process are solved.

Disclosed are a positive electrode slurry, a positive electrode sheet, and an electrochemical device containing same. The positive electrode slurry comprises a positive electrode active material, a binder, and a dispersant. The dispersant comprises component A and component B. Component A is an acidic dispersant, component B is an alkaline dispersant, and the mass ratio of component A to component B is (1-30):1. The positive electrode active material comprises carbon-coated lithium iron phosphate. The binder comprises polyvinylidene fluoride. The positive electrode slurry uses a composite dispersant comprising two different components, and has good coating performance and excellent bonding performance. A positive electrode sheet prepared using the positive electrode slurry has high peel strength, and the resulting electrochemical device (especially a lithium-ion battery) has excellent capacity retention.

The invention provides a lithium iron phosphate material and a preparation method thereof, a positive pole piece and a lithium ion battery, the preparation method comprises the following steps: dissolving a soluble iron salt and a ligand in water to form an iron-based complex so as to obtain a first solution; placing the carboxylated cellulose material in a first solution to form an iron-cellulose complex, so as to obtain a first mixed material; carrying out first separation and drying on the first mixed material to obtain an iron-cellulose complex; and mixing a lithium source, an iron source, a phosphorus source, a carbon source and the iron-cellulose complex in a solvent, heating, carrying out second separation on the obtained reaction mixture, and sintering the obtained solid to obtain the lithium iron phosphate material. According to the method, an iron-cellulose complex is used as a one-dimensional structure template, the lithium iron phosphate material with a one-to-many electron transport mechanism is successfully constructed, the conductivity, the rate capability and the working voltage of the material are improved, and the problem of capacity fading of the lithium iron phosphate material under high current density is further solved.

The invention discloses a life expectancy estimation method and system for a hybrid energy storage system. The hybrid energy storage system is composed of an aqueous hydrogen ion battery and a lithium iron phosphate battery. The method comprises the following steps: defining basic parameters and operation boundary conditions of a single battery, and constructing a sub-battery aging sub-model based on two battery aging paths; operating data are collected through a mixed working condition acceleration test, differential temperature correction coefficients are calculated, and an interaction influence factor library is formed through quantification; adopting a BiLSTM neural network to complement the full life cycle data and optimize the sub-model; and integrating the multi-dimensional correction factors to calculate the corrected service life of the single battery, determining the expected service life of the system in combination with a preset judgment rule, and realizing model iterative optimization through actual operation data comparison. The system comprises a parameter defining and model building module, a data collecting and processing module, a data complementing and model optimizing module, a service life estimating module and an iterative optimizing module. According to the invention, the accuracy and adaptability of life expectancy estimation are improved, and large-scale application of the hybrid energy storage system is supported.

The invention relates to a composite positive electrode material and a preparation method thereof, a positive plate and a battery in the technical field of lithium battery production. The composite positive electrode material comprises a core part of a lithium manganate positive electrode material and a coating layer positioned on the surface of the core part, the coating layer comprises a first coating layer and a second coating layer, and the first coating layer is positioned between the core surface of the lithium manganate positive electrode material and the second coating layer; the first coating layer is nickel cobalt lithium manganate (NCM), and the second coating layer is lithium iron phosphate (LFP). Through the synergistic protection effect of double-layer coating, the stability of the lithium manganate structure can be remarkably enhanced, and the high-temperature storage performance and the cycle performance of the battery cell are improved.

The invention discloses a water-based fire extinguishing agent based on inorganic silicon dioxide aerogel loaded metal oxide nanoparticles, a preparation method and application. The fire extinguishing agent is prepared from, by mass, 1%-5% of silicon dioxide aerogel loaded metal oxide nanoparticles, 1%-10% of a foaming agent, 0.1%-2% of a stabilizer, 1%-10% of a flame retardant, 0.5%-5% of an anti-freezing agent, 0.1%-1% of a preservative and the balance water. The silicon dioxide aerogel loaded metal oxide nano-particles are prepared by the following steps: preparing a silicon dioxide aerogel skeleton, preparing metal oxide nano-particles, and modifying, loading and drying silane. The preparation method comprises the following steps: firstly preparing a dispersion liquid A containing the composite particles and a solution B containing the functional additive, and then carrying out mixing and ultrasonic treatment to obtain the product. The fire extinguishing agent can rapidly extinguish 314Ah lithium iron phosphate battery fire, efficiently consumes HF / CO and other gases, and is stable in system, environmentally friendly and suitable for battery fire prevention and control.

The invention provides a method for separating and recycling positive and negative electrode materials of a waste lithium iron phosphate liquid injection battery cell. The method comprises the following steps: carrying out mechanical and physical treatment on the waste lithium iron phosphate liquid injection battery cell to obtain a pole piece mixed material; mixing the pole piece mixed material with a negative electrode binder denaturant, and then carrying out calcination treatment to obtain a calcined product; screening the calcined product to obtain an undersize product and an oversize product, the undersize product being a positive electrode material, and the oversize product comprising a negative electrode sheet and an aluminum foil; and carrying out post-treatment on the oversize product to respectively obtain the negative electrode material and the current collector recycled material. According to the method, the negative electrode binder is not decomposed during calcination by adding the negative electrode binder denaturing agent by utilizing the pyrolysis behavior difference of the positive and negative electrode binders, so that the combination of the negative electrode material and the current collector is stabilized, and the selective separation of the positive electrode material and the current collector is realized. The positive electrode material separated by the method can meet subsequent repair requirements, use of acid recovered by a black powder wet method is reduced, and the process cost is remarkably reduced.

The invention provides a method for recycling lithium from waste lithium iron phosphate batteries. The method comprises the following steps: pretreating the waste lithium iron phosphate battery to obtain positive electrode powder; mixing the positive electrode powder, the buffer leaching agent solution and the lithium salt seed crystal suspension, and carrying out leaching reaction to obtain a lithium-rich leaching solution; and carrying out post-treatment on the lithium-rich lixivium to prepare a lithium salt product. According to the method, the buffer leaching agent solution and the lithium salt seed crystal suspension are adopted to play a synergistic effect, the selective leaching efficiency of lithium can be effectively improved, and the buffer leaching agent not only can destroy the lattice structure of the positive electrode material and promote dissolution of lithium ions, but also can effectively relieve pH fluctuation to avoid generation of impurity colloids; the lithium salt seed crystal suspension can further reduce co-dissolution of transition metal ions and other impurities through the same ion effect, so that the finally prepared lithium salt product is high in purity and high in yield.

The invention aims to provide a lithium iron phosphate battery pack parallel current sharing control method and system, and aims to solve the problem of non-uniform current distribution caused by dynamic change of internal resistance of lithium iron phosphate batteries in the prior art, and the technical problems that a traditional PI controller is slow in response speed, and current impact and voltage fluctuation are easily generated during load sudden change. According to the technical scheme provided by the invention, by establishing a virtual impedance adaptive adjustment mechanism based on depth model predictive control and combining with the adaptive PID controller optimized by reinforcement learning, accurate balance control on the current of each parallel battery pack is realized, and meanwhile, the method has fault detection and reconstruction capabilities and ensures stable operation of the system under various working conditions.

The invention discloses a polymeric dispersant for lithium iron phosphate and lithium iron manganese phosphate positive electrode slurry and a preparation method, and relates to the technical field of preparation of lithium ion battery positive electrode materials. The dispersing agent is a segmented copolymer obtained by synchronously dropwise adding free radicals to polymerize a nitrogen heterocyclic ring-containing monomer and a carboxylic acid group-containing monomer, the number-average molecular weight is 10000-50000, and the molecular weight distribution is 1.5-3.0. The dispersing agent is adaptive to an LFP / LMFP dual system, has excellent dispersing performance, can reduce the viscosity of LMFP slurry to 3800 mPa.s or below, can increase the solid content of the LFP slurry to 75% or above, and has the 24-hour sedimentation rate lt; 1.5% by weight; the 3C / 0.2 C discharge ratio of the battery using the dispersing agent is greater than or equal to 88% and 2000, the selected monomers are low in cost, expensive synergists are not needed, and the dispersing agent has remarkable industrial advantages.

The invention belongs to the technical field of new energy, and particularly relates to a lithium iron phosphate material and a preparation method and application thereof. According to the preparation method of the lithium iron phosphate material, provided by the invention, a compact and uniform nanoscale oxide protection layer is constructed by utilizing melting, infiltration and subsequent oxidation behaviors of low-melting-point metal components under specific conditions, the electronic conductivity and the structural stability of the material are effectively improved, and through the grading of large particles and small particles, the performance of the lithium iron phosphate material is improved. The lithium iron phosphate material has high compaction density and excellent high-rate charge-discharge performance and cycle performance; besides, the coating process and the synthesis process of the lithium iron phosphate are synchronously completed by adopting an integrated process of mixing, sintering and oxidizing, a complicated post-treatment coating step is not needed, the process flow is short, and the method is suitable for large-scale production.

The invention discloses a vanadium iron-site doped iron phosphate material and a preparation method, and relates to the technical field of lithium ion battery positive electrode material preparation, pure water is used as a base solution, and a vanadium salt solution with the pH value of 2.0-3.0, a ferrite solution with the pH value of 1.0-2.5 and a phosphorus-oxygen mixed solution with the pH value of 5.0-7.0 are simultaneously added into a reaction kettle in a three-strand parallel flow mode for a co-precipitation reaction. By controlling the acid environment of a key solution system, reduction of metavanadate radicals or generation of ferric vanadate precipitates is effectively inhibited, and vanadium elements are successfully and uniformly doped to iron sites of iron phosphate crystal lattices; the mass ratio of iron to phosphorus in the obtained iron phosphate material is stabilized at 95-98%, the doping amount of vanadium is 100-10000 ppm, and the vanadium is uniformly distributed. Lithium iron phosphate prepared by taking the material as a precursor has higher discharge capacity and compaction density, and the electrochemical performance of a lithium ion battery is remarkably improved.

The invention discloses battery-grade iron phosphate as well as a preparation method and application thereof. The battery-grade iron phosphate is of a core-shell structure, D50 is 20-40 [mu] m, the core is 50% of an internal area in the radius direction, the shell is the other external area, the porosity of the core is 1%-10%, the porosity of the shell is 30%-70%, and when the battery-grade iron phosphate is used for preparing a lithium iron phosphate material, natural grading can be achieved without iron phosphate compounding; the prepared lithium iron phosphate material has high compaction density.

The invention relates to the technical field of energy storage and energy management, in particular to a lithium iron phosphate energy storage scheduling method for an industrial park. The equivalent life loss cost is introduced into a scheduling target and is determined by the discharge depth, the charge-discharge rate, the temperature and the health state parameters of the energy storage monomers, so that the long-term total cost of the park is taken as an optimization target. A multi-time-scale control framework is adopted, an upper-layer rolling robust optimizer generates an energy storage power predicted value and adds risk constraints, and a lower-layer real-time scheduler corrects power according to deviations and emergency states and distributes the power in a layered mode according to a load priority list. The parallel energy storage monomers distribute power in a weighted mode according to the health state, the charge state, the temperature and the internal resistance, the digital twin module predicts the attenuation rate and a maintenance window, and the health state is fed back to be optimized and dispatched. In the switching process, output is smoothly adjusted according to an energy retention boundary and a stepped discharge strategy, so that the comprehensive overhead of electric energy cost and service life cost is reduced, and the service life of the lithium iron phosphate battery is prolonged.

The invention discloses a method for selectively recovering lithium from waste lithium iron phosphate batteries. The method comprises the following steps: carrying out ball milling activation on waste lithium iron phosphate powder and a grinding aid to obtain activated powder; and the activated powder is leached through an organic acid-hydrogen peroxide mixed leaching agent, slag and a lithium-containing solution are obtained, the lithium-containing solution is subjected to aftertreatment, and a lithium-containing compound is obtained through recycling. According to the method provided by the invention, through the synergistic cooperation of mechanical ball-milling activation and the specific organic acid-hydrogen peroxide system leaching agent, the use amount of leaching acid and the leaching temperature are reduced, the leaching rate and the recovery rate of lithium are improved, and meanwhile, the method is environment-friendly and is suitable for industrial production. And the resource recycling technology of the waste lithium iron phosphate battery is promoted to develop towards the green, efficient and economic direction.

The invention relates to the technical field of preparation of positive electrode materials, and discloses a method for preparing a lithium iron phosphate positive electrode material from an atom-doped carbon coating layer, in particular to a method for preparing a lithium iron phosphate positive electrode material from the carbon coating layer on the surface of the lithium iron phosphate positive electrode material containing a plurality of heteroatoms M, and the molecular formula of the heteroatoms M is LiFePO4 / C (at) M. The preparation method comprises the steps of grinding twice and sintering, the structure of the carbon material is adjusted by utilizing the synergistic coupling characteristic of doped atoms, and the high electron mobility and ion mobility of the lithium iron phosphate positive electrode material are enhanced. The prepared positive electrode material has excellent electrochemical performance, and the charge-discharge specific capacity and the rate capability are improved.

The invention discloses a marine geomagnetic diurnal variation station, which comprises a pressure-resistant sealed cabin, a proton precession magnetometer system for measuring the intensity of a geomagnetic field, a power supply system integrated in the pressure-resistant sealed cabin, a positioning and time synchronization module, an environment monitoring unit and the like, and is characterized in that the pressure-resistant sealed cabin is of a glass floating ball structure, and the interior of the pressure-resistant sealed cabin is divided into an upper part and a lower part; the power supply system comprises a plurality of lithium iron phosphate batteries, and the host unit comprises a CPU board, a simulation board and the like, and is further provided with a deck control unit and the like. The geomagnetic field intensity can be accurately measured, interference is reduced through the watertight cable structure, position information and time calibration can be provided, the internal state of the cabin can be monitored, parameter configuration, data export and other functions can be achieved, the device can work well on the land and in the deep sea, and the alarm can be triggered when abnormity occurs.

The utility model relates to an energy storage system based on fire fighting, which comprises a battery system. A smoke exhaust pipeline system and a fire extinguishing pipeline system are respectively arranged on the battery system; the battery pack comprises a battery shell; a plurality of battery cell spacers are arranged in the battery shell and divide a closed inner cavity of the battery shell into a plurality of independent battery chambers for storing lithium iron phosphate battery cells; a communication channel is arranged in the battery shell; the communicating channel comprises a smoke collecting chamber and a medicament fire extinguishing chamber; the smoke collecting chamber is communicated with the medicament fire extinguishing chamber through a common through hole; the smoke collecting chamber and the medicament fire extinguishing chamber are respectively communicated with a smoke discharging pipeline system and a fire extinguishing pipeline system; a VOC composite detector is arranged in the closed inner cavity; the device is reasonable in design, compact in structure and convenient to use.