Description
1. The Significance of Slurry Resistivity
The slurry is an important intermediate product in the production of lithium-ion batteries. The uniformity and stability of the slurry greatly affect the consistency and electrochemical performance of the final battery cell. The current method of monitoring slurry only has viscosity parameters, which cannot accurately evalu- ate the uniformity and stability of its electrical proper- ties. However, the slurry conductivity parameters and slurry formulation, conductive agent type and content, binder type andcontent etc, which all have significant correlation to monitor the production of slurry, and the slurry may have gel sedimentation after dwelling for a period of time after mixing. At this time, the conductivity value will also show varying degrees of change. Therefore, the conductivity of the slurry can be used as a method to characterize the uniformity and stability of the electrical properties of the slurry.
Monitoring the conductivity of the slurry, not only , it can evaluate the infuence of diferent active materials.conductive agents, binders, solid content, etc, on the electrochemical performance of the slurry, but alsoit can also be used for, monitoring the process stability, which can quickly identify abnormalities in the mixingprocess, and avoid the waste of time and cost caused by defective slurry flowing into the subsequent process.
2. Battery Slurry Resistivity Test Principle
Test steps: Putting a certain volume of slurry (~80mL) into the measuring glass, inserting a clean electrode pen, start the software, start to test the changes in the slurry resistivity at the three pairs of electrodes over time and save it in the file.
Test parameters: Resistivity, Temperature, Time
Calculation formula:
Features:
- Applicable to the conductivity evaluation of lithium (sodium) slurry and conductive agent slurry, to assist in research and development.
- Separate the voltage and current lines, eliminate the influence of inductanceon voltage measurement, and improve the accuracy of resistivity detection.
- The disc electrode with a diameter of 10mm ensures a relatively large contactarea with the sample and reduces the test error.
- Three pairs of electrodes test the slurry resistivity and identify the slurry sedimentation performance.
- Monitoring the changes of resistivity ofthe slurry in real time at threepositions in the vertical direction over time.
3. Slurry Resistivity Analyzer MSA
Test program: Three operators, five parallelsamples, and random testing
Test method: Sonicating the electrode pen withdeionized water for 30 seconds,and drying it with the dust-freepaper. Then five parallel sampleswas tested, and the fifth set of datawas taken for the GRR analysis
4. Applications
Applications
Case 1. Evaluation of Conductive Agent Slumy With Different Fommulations
- When the viscosity, concentration and dispersant type of the conductive agent are changed, the resistivity also changes!
- In the future, specifications can be forrmulated for the slurry resistivity of a certain fixed viscosity, and the stability of the slurry process can be monitored!
Case 2. Concentration-Viscosity-Resistivity Correlation
- The resistivity of the slurry decreases with the increase of the concentration, and the change of the viscosity is also inversely proportional to the relationship;
- The I-V curve test of these two types of slurries basically conforms to Ohm’s law, and the current and voltage have a linear relationship, indicating that the slurries are mainly electronic conductors;
Case 3. Slurry Settling Performance
- On the first and fourth day of testing, the resistivity of the upper and middle channels increased, while the resistivity of the lower channel decreased, indicating that after four days of shelving, the slurry shows obvious settlement.
- Subsequently, a shelving period can be formulated for a certain of slurry according to the change of the resistivity to ensure the uniformity of the slurry!
Video
Specifications
