Inventory of experimental instruments: Preparation of PVDF-coated modified lithium battery separators on polyolefin separators

The new energy vehicle industry is the direction of the country's heavy investment in research and development, and lithium batteries are the key components of new energy vehicles, so the demand for lithium batteries continues to grow. The performance of the lithium battery separator affects the safety performance and excellent electrical performance of the lithium battery, so the performance requirements for the lithium battery separator are more stringent. Aiming at some disadvantages in the performance of existing lithium batteries, student Song from Hebei University and his supervisor conducted research on modified lithium battery separators.

In the experiment of "Preparation and Performance Research of Lithium-ion Lithium Battery Diaphragm for Electric Vehicles", student Song first prepared PVDF slurry for coating modification, and then used PVDF slurry to coat polyolefin separator on one or both sides. Cloth preparation for coating modified separators. Finally, perform performance testing on the modified lithium battery separator, including thickness, air permeability, mechanical properties, puncture strength, glass strength, heat resistance dimensional stability test, electrolyte adsorption capacity and retention capacity test, and ion conductivity test.

Today Xiaochao made an inventory of the testing instruments used in this experiment, see the table below for details (the instruments are not exactly the same, but the technical parameters are basically close ):

Membrane Proofing- Membrane
	Wire rod scraper integrated coating testing machine
	Specification parameters: Coating thickness 0.01-10mm, scraper can be raised and lowered, coating speed 2~200mm/s, coating width 300*400mm (coating length 0-400mm can be set arbitrarily), coating time digital display, different speed, time Accuracy control, coating rod specifications are equipped with 1 domestic wire rod and 1 imported wire rod with a precision up to 1μm, coating width 300mm, scraper length 400MM material/stainless steel, power supply voltage 220V 50HZ 1700W, machine volume 626*410* 520 (length*width*height), machine weight net weight 55KG, speed control infinitely variable speed, bottom plate material glass, optional accessories leakage tank, base material fixing fixture, fine-tuning leveling height support leg device, glass plate, silicone pad and weight (Aiming at the application of uneven thickness of coated substrates), the function of jet system device, UV solid-holding device, automatic ink filling system can be customized
Physical Properties - Moisture
	Zibo Coulomb SF-1 Trace Moisture Analyzer
	Specification parameters: measurement method Karl Fischer coulometric method, 4-digit LED digital display on the display screen, readout unit μgH2O, measurement range 5μg~80mg (H2O), moisture measurement accuracy 5μg~1mgH2O is not more than ±0.3%; more than 1mg H2O is not more than ±0.5%. (not including sampling error), automatic control of electrolysis current 0-300mA, sensitive valve 1μgH2O, power consumption not greater than 40W, ambient temperature 5-40°C, ambient humidity ≤85%, overall size 430*230*180mm, weight about 5.8 kg
Mechanical Properties - Tensile Compression
	Farui FR-103C Tensile Testing Machine
	Specification parameters: Maximum test force 100N, 200N, 500N, 1KN, 2KN, 5KN 10KN 20KN, choose one within 30KN. , the accuracy level is 0.5, the force value measurement range is 0.2~100%, the force value accuracy is <±0.5%, the maximum force value resolution is 1/1000000, the inside and outside are not divided into files, and the resolution of the whole process remains the same, the load sensor Basic configuration: one tension and compression sensor (maximum load) Extended configuration: multiple sensors can be added, effective test width 400mm (can be widened according to customer requirements), effective stretching space 400, 500, 700mm (can be increased according to customer requirements) High), the test speed range is 0.001~500mm/min, the displacement resolution is within ±0.2% of the indicated value, the deformation measurement system configuration: large deformation: minimum gauge length 10mm, deformation range: 800mm large deformation indication error: Within ±0.5%; large deformation measurement resolution: 0.008mm, deformation measurement accuracy within ±0.5% of the indicated value (large deformation or small deformation can be selected according to customer requirements), test bench safety device electronic limit protection, test bench lift The device jogs, the test bench return function includes manual or automatic function, automatically or manually returns to the test initial position at the highest speed after the test, overload protection exceeds the maximum load of 10%, automatic protection of the machine, a set of tensile fixtures for the fixture, the size of the main machine 700*530*2200 mm, power system servo motor + drive + high-precision ball screw, power supply voltage 220V, 50HZ, power 0.75KW (according to different force requirements, different power motors are standard), the weight of the host is about 500Kg, accurate Degree Level 0.5
	ASR-1001A small multifunctional material Tensile Testing Machine
	Specification parameters: force measurement range 10~500N (50KG), effective stroke 350mm, induction push-pull force gauge, test speed range 5~300mm/min adjustable, power system AC motor, overall size 560×345×1080mm, weight 30Kg , power supply voltage AC220V single phase
Physical Properties - Air Permeability
	Yongxin Instrument ZQX-1000 Paper Air Permeability Meter
	Specification parameters: Measuring range 0~1000ml/min, test area 10±0.02cm², test area pressure difference 1±0.01kPa, measurement accuracy±1ml(<100ml);±5ml(>100ml), clamp ring inner diameter 35.68±0.05mm , The coaxiality of the center hole of the upper and lower clamp rings <0.05mm
	Pinxiang PN-ZQX1000 Paper Air Permeability Tester
	Specification parameters: Measuring range 0~1000ml/min or 0~17µm/(Pa·s), test area 10±0.02cm², test area pressure difference 1±0.01Kpa, measurement accuracy±1ml(<100ml);±5ml(> 100ml), the inner diameter of the clamp ring is 35.68±0.05mm, and the coaxiality of the center hole of the upper and lower clamp rings is <0.05mm
Environmental testing - temperature and humidity control
	Tester 101-1AB Electric Forced Air Drying Oven
	Specification parameters: temperature control range RT+10~250°C, temperature fluctuation ±1.0°C, temperature resolution 0.1°C, temperature uniformity ±2.5%, volume 71L, studio size 450*350*450mm, studio material high-strength carbon Steel plate, shelves (standard) 2pcs, maximum number of shelves 13pcs, maximum load of a single shelf 15kg, timing range 0~9999 minutes (with timing waiting function), power supply voltage AC220V/7.3A 50/60Hz, input power 1.6KW , Dimensions 752*520*680mm, net weight 40kg, outer box material cold-rolled steel plate, surface chemical resistance coating, thermal insulation material aluminum silicate fiber, heater stainless steel heating tube, exhaust port inner diameter 28mm*2, rear Top test hole, thermostat digital tube double column PID, temperature setting method, touch four buttons to set, temperature display method, measurement temperature display: 4-digit digital upper display; set temperature display: 4-digit digital lower display , operation function fixed value operation, timing operation, automatic stop, optional program mode, additional function deviation correction, menu key lock, power failure compensation, power failure memory, temperature sensor pt100, outer packaging size 875*595*812mm, partition spacing 25mm , gross weight 50kg, 4 shelves (standard), optional accessories partition, RS485 interface, printer, Recorder, external communication, remote control, program temperature controller, wireless SMS alarm, U disk data storage
Raw material performance testing - fineness
	Jingxin JL-6000 wet and dry laser particle size analyzer
	Specifications:Measuring principle Full-scale Mie scattering theory and our proprietary technology calculation, in line with ISO 13320 and other international standard principles, measuring range 0.02µm~2000µm (wet method); 0.02µm~2000µm (dry method), quality requirements according to Q/70920531- 0.1-2016 standard, check and accept with standard powder, repeatability error 50% volume cumulative particle size value repeatability dry method <3%, wet method <1% (national standard substance), signal light source imported semiconductor laser, dual light source design, main Laser wavelength 635nm, 50mw, lifetime > 25000h Cross auxiliary violet light source: wavelength 405nm, optical path design implements ISO13320, ISO13321 and other international standard principles. The inverted Fourier optical path design is adopted to reduce the stray light generated by the multiple reflections between the sample cell and the optical mirror, the optical path is automatically centered, and the photoDetectors are 92-level multi-element Detectors, which are arranged in front, rear and side three-dimensionally (patent) Max. The detection angle is 165 degrees, the dry method of dispersion medium: compressed air/if the powder is to burn after contacting with air, inert gas such as nitrogen needs to be selected; the wet method: tap water, distilled water or other liquids, the dry method of dispersion method: unique sampling device ( patent), with the cooperation of Air Compressor high-pressure airflow and dust extractor, etc., the measured powder is pumped and sprayed to the test area, and the dispersion time is less than 5 seconds; wet method: put the measured powder into the sample pool, and the ultrasonic disperser , Stir evenly, and then circulate the dispersed powder to the test area, the dispersion time is less than 15 seconds, the sample amount is about 0.1-2g each time for wet method, and about 1g-10g/each time for dry method, determined according to the characteristics of the sample, data Processing data processing, the test software runs XP/win7 operating system, the result format has a variety of different report formats, including cumulative particle size distribution data and curves, interval particle size distribution data and histograms, typical particle size values such as D3, D10, For data such as D25, D50, D75, D84, D90, D97, volume average particle size, area average particle size, and specific surface area, the result format can be modified or edited as required. The output results can be printed directly, or converted into BMP images, PDF and text files and saved in formats such as Chinese and English versions for users to choose. , working power supply ~ 220V±22V 50Hz±0.5 Hz, environmental requirements, the use environment should be clean, temperature: 5°C -35°C, main machine size 850*450*420mm, auxiliary machine 660*320*900mm, weight 150kg
General Laboratory Equipment - Quality
	Huazhi PTX-JA1000 Analytical Balance
	Specification parameters: Weighing range 1000g, minimum weighing value 1mg, readability accuracy 1mg, repeatability error ± 1mg, external calibration for calibration function, adjustable stabilization time, working conditions 10°C – 30°C, 80%RH, Non-condensing, weighing pan size Ф128mm, external dimension 345*223*331mm, data interface RS-232, display LCD large interface backlight display, bottom shell made of aluminum alloy, linear error ± 3mg

The above are the main experimental instruments. In the experiment, the researchers used the spray coating method to prepare the thin film, but for the lithium battery separator coated on the thin film, an automatic film coating machine can also be used for scraping. According to this experimental research, the overall effect of the surface PVDF modified lithium battery separator is still good, and it is also worthy of reference for other users. Its performance can better meet the performance requirements of new energy vehicles for lithium batteries.