Powder conductivity testing - Delft Solids Solutions

Upon handling and using solids and powdery materials, physical properties are of great importance. One of the physical properties is the electrical conductivity of a powder material. In various industries it is important to know to what extent a powder conducts current. These properties can be of importance in, for example, the battery industry where the cathode or anode are coated with powder and it is important that powders have a low resistance that is high conductivity. Contrarily, for calcium carbonate powders which are used as fillers for example in various industries, it is desirable to have a high resistance, thus low conductivity.

Measuring the electrical resistance of powders is not straightforward. Powder, unlike liquids or solids blocks, do not have a continuous phase. Therefore measuring the electrical conductivity not solely depends on concentration, but is also influenced by particle size, void space, pressure applied, the method of applying pressure and the strength and frequency of the current used to measure the conductivity. As a result, a special setup is required that allows the electrical resistance of powders to be determined. Furthermore, it is also important to perform a standard method while measuring the electrical conductivity, to compare results and draw conclusions.

At Delft Solids Solutions, we operate various setups to measure the electrical conductivity of powders. This enables us to measure powders with a high conductivity like carbon blacks and metal powders, as well as powders with a low electrical conductivity such as polymers. In addition, the equipment is capable of applying various pressures, which as far as possible is in line with the conditions used during actual processing or in a certain unit operation, and therefore determine the conductivity of a powder during its actual use.