IEST Powder Resistivity & Compaction Density Measurement System (PRCD3100)

Powder Resistivity & Compaction Density Tester(PRCD) Series Detailed Operation Video

1. The Significance of Powder Resistance

The rate performance of lithium-ion batteries(LIBs) is closely relatedto the battery resistance. The battery resistance includes ionic resis-tance and electronic resistance. The ionic resistance mainly refers tothe resistance of lithium ions in the electrolyte in the electrodepores, the resistance of lithium ions through the solid electrolyte interphase(SEl),the chargetransfer resistance of the lithium ions and electrons at the interfaceof the active material/SEl , and the solid diffusion resistance of thelithium ions in the active material. The electronic resistance mainlyrefers to the resistance of the positive and negative active materialsthe current collector resistance, the contact resistance between theactive materials, the contact resistance between the active materialand the collector, and the welding resistance of tabs. in the practical production process of LIBs, the ionic resistance partneeds to be evaluated by using the finished product. However,the electronic resistance part can be quickly evaluated byusing the materials and electrodes. Therefore, the accurate evaluation of the electronic resistance of the materials andelectrodes is of great significance for predicting the resistance of the LIBs.

2. Measurement System Analyze

Test condition: 5 samples, 3 operators, 3 times/pcs/operator

3. Applictions

4. Application cases

4.1 LCO Material Assessment: Evaluation of electrical properties of modified powder 

• Parameter: 10~200MPa, 5MPa steps (15s)
• Results: When the Compact density of the modified powder is greater than 3.87g/cm³ (applied pressure > 75MPa), the conductivity of the modified powder is greatly improved.
• The effectiveness of the modification can be evaluated.

4.2 NCM Material Assessment: Relation of powder resistivity and electrode

• By adjusting the Ni content in the ternary material, the powder conductivity increases with the increase of Ni content.
• Compared with three kinds of ternary electrodes with different Ni content, the conductivity of the electrode increases with the increasing of Ni content.
• We can concludes that powder resistivity and electrode have the same behavior.

4.3 NCMA Material Assessment: Relation of powder resistivity and electrode

• The conductivity trend of the Quaternary powder and electrode under three different modification conditions is NCMAT > NCMA-2 > NCMA-3 ;
• The conductivity of NCMA43 in powder state is much smaller than that of the former two samples, but there is a small difference in the electrode plate, which may be related to the addition of conductive in the electrode plate, which reduces the difference between the powder.
• Powder resistivity and electrode have the same trend.

4.4 LFP Material Assessment: Relation of powder resistivity and electrode

 

• Compared with the LFP powder and electrode sheet under four different modification conditions, the conductivity trend of LFP powder and electrode sheet is as follows: LFP-1>LFP-2>LFP-3>LFP-4
• Powder resistivity and electrode have the same trend.

4.5 Graphite Material Assessment: Compact density: parallel test 5 times

• The cov of five parallel samples is less than 0.1% in the whole pressure range, which indicates that the equipment has good repeatability.
• With the increase of pressure, the Compact density of graphite material increases gradually and tends to be flat.
• The rebound thickness of graphite powder under compression and decompression process reaches the maximum value at 80MPa, which indicates that this pressure is the maximum pressure that the powder can bear if continue to increase the pressure, the structure of the material will be damaged.

4.6 Carbon Material Assessment: Compact density VS resistivity: parallel test 5 times

• Parameter: relief mode: 10~200MPa, 10MPa steps, keep 10s
• The cov of five parallel samples is less than 0.3% in the whole pressure range, which indicates that the equipment has good repeatability.
• With the increase of pressure, the compact density of carbon material increases gradually, and the compaction range is 0.5-0.9 g /cm³ .

 

High accuracy pressure system : Driven  by servo motor.

High accuracy displacement sensor : Precisely measure the variation of thickness.

Specific clamp for resistivity & Compact density test of powder samples : Simplify the process of the powder loading and cleaning.

Multi-functions : One-stop data collection of key parameters of pressure, resistance, thickness, temperature and humidity with high reliability, to provide a complete traceability for each result.

Automatic measurement : Providing flexible measurement modes for different kinds of samples, and all the process parameter setting are integrated into a simple software control interface, with one-button to start a measurement

PRCDMS Software:

1.Pressure can be set willfully within the extent of max pressure.

2.The resistivity under different pressure can be measured in succession with controllable rate and interval of pressure scan.

3.Different data analysis curves can be generated, including resistivity-pressure curve, resistivity-thickness curve, Compact density-pressure curve, and pressure-thickness curve.

4.Two resistance data collection modes: interval time mode or automatic steady state condition determine mode.

5.Data statistical analysis functions.

6.Automatic generation of reports with the value of resistivity (or conductivity) and Compact density.

Integrated design :Integration of control and measurement systems for pressure, resistivity and thickness control and measurement systems.