The spodumene concentrate is then further refined and processed into high purity / battery grade Lithium Hydroxide or Lithium Carbonate (~99. 5%) through many process stages including primary and secondary filtration steps requiring consumable filter media, filter fabric, filter cloths, filter belts and filter bags.
How is a lithium ion battery made?
A lithium ion battery is primarily comprised of electrodes (cathode and anode), separators and an electrolyte solution. The manufacturing process, which is outlined in Figure 1, involves forming the electrodes, stacking the cells, adding the electrolyte solution, charging the battery, aging and final inspection.
Filtration has been found to significantly improve battery quality and performance. Proper filter selection is required to remove particulate contaminants and gels from solvents, water and the high viscosity slurries used in forming the electrodes. Filters are also needed to remove particle contamination during the electrolyte filling process.
Which filter media is suitable for battery electrolytes?
Since electrolyte constituents vary considerably among battery manufacturers, the appropriate filter needs to be determined in each case. As indicated in Figure 8, Pall has a number of different filter media that are suitable for use with battery electrolytes: polytetrafluoroethylene (PTFE), high density polyethylene (HDPE) and polypropylene (PP).
What is a lithium electrolyte?
The electrolyte is typically comprised of lithium salts (e.g, LiPF6 or LiBF4) in organic solvents, such as ethylene carbonate (EC) or dimethyl carbonate (DMC). These salts may not completely dissolve in the solvents, and consequently must be removed by filtration.
Why is Filter selection important in filtering slurries?
When filtering slurries, filter selection is critical. The filter must allow the desired particles to pass through, while simultaneously retaining oversized particles. This must be accomplished without plugging the filter and consequently shortening its service life.
How does a slurry filter work?
As the fluid goes through the filter, the pores become finer, removing ever smaller oversized particles. Because of the filter's very sharp particle size cut-off, virtually all of the desired active slurry material is able to pass through the filter.