6.2 Lithium Batteries and Lithium-Ion Batteries
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polypropylene (PP) is placed in the outer layer and polyethylene (PE) is placed
in the inner layer, which increases the oxidation resistance of the separator.
8. Space stability
When the diaphragm is removed, the edges must be flat and not curled to prevent
the battery assembly from becoming complicated. Diaphragms do not collapse
when they are immersed in the electrolyte.
9. Puncture strengths
The separator used for the winding battery has a high requirement for the puncture strength so that the electrode material does not pass through the separator. If
part of the electrode material penetrates the separator, a short circuit will occur,
and the battery will be wasted. For the separator, the lithium-ion batteries require
higher puncture strength than the lithium primary battery.
10. Mechanical strength
The sensitivity of the separator to the penetration of the electrode material particles is characterized by the mechanical strength. During the winding process,
the electrode generates a large mechanical stress between the anode-separatornegative electrode interface, and some looser particles may forcibly penetrate
the separator. Short the battery.
11. Thermal stability
Water in lithium-ion batteries is detrimental, so the electrodes are usually dried
under vacuum drying at 80 °C. Therefore, under these conditions, the separators
must not shrink significantly. Each battery manufacturer has its own unique
dryness. The process requirements for lithium-ion secondary battery separators
are drying at 90 °C for 60 min, the transverse and longitudinal shrinkage of the
diaphragm should be less than 5%.
12. Aperture
For lithium-ion battery separators, because the most critical requirement is to
not allow lithium branches to pass through, separators with submicron pore
sizes are suitable for lithium-ion batteries.
13. High-temperature stabilities
In high temperature conditions, the diaphragm is needed to stem the mutual
transmission between the electrodes. The high temperature stability of the separator was characterized using thermomechanical analysis (TMA). The so-called
TMA is to determine the ratio of diaphragm growth and temperature under
certain load conditions.
14. Electrode interfaces
The separator and the electrode should provide a good interface for electrolyte
flow.
In addition to the above requirements, the diaphragm should also overcome
the following defects: pinholes, wrinkles, gels, dirt, etc. Before the application of
the lithium-ion battery, all the above characteristics of the diaphragm should be
optimized.
143
polypropylene (PP) is placed in the outer layer and polyethylene (PE) is placed
in the inner layer, which increases the oxidation resistance of the separator.
8. Space stability
When the diaphragm is removed, the edges must be flat and not curled to prevent
the battery assembly from becoming complicated. Diaphragms do not collapse
when they are immersed in the electrolyte.
9. Puncture strengths
The separator used for the winding battery has a high requirement for the puncture strength so that the electrode material does not pass through the separator. If
part of the electrode material penetrates the separator, a short circuit will occur,
and the battery will be wasted. For the separator, the lithium-ion batteries require
higher puncture strength than the lithium primary battery.
10. Mechanical strength
The sensitivity of the separator to the penetration of the electrode material particles is characterized by the mechanical strength. During the winding process,
the electrode generates a large mechanical stress between the anode-separatornegative electrode interface, and some looser particles may forcibly penetrate
the separator. Short the battery.
11. Thermal stability
Water in lithium-ion batteries is detrimental, so the electrodes are usually dried
under vacuum drying at 80 °C. Therefore, under these conditions, the separators
must not shrink significantly. Each battery manufacturer has its own unique
dryness. The process requirements for lithium-ion secondary battery separators
are drying at 90 °C for 60 min, the transverse and longitudinal shrinkage of the
diaphragm should be less than 5%.
12. Aperture
For lithium-ion battery separators, because the most critical requirement is to
not allow lithium branches to pass through, separators with submicron pore
sizes are suitable for lithium-ion batteries.
13. High-temperature stabilities
In high temperature conditions, the diaphragm is needed to stem the mutual
transmission between the electrodes. The high temperature stability of the separator was characterized using thermomechanical analysis (TMA). The so-called
TMA is to determine the ratio of diaphragm growth and temperature under
certain load conditions.
14. Electrode interfaces
The separator and the electrode should provide a good interface for electrolyte
flow.
In addition to the above requirements, the diaphragm should also overcome
the following defects: pinholes, wrinkles, gels, dirt, etc. Before the application of
the lithium-ion battery, all the above characteristics of the diaphragm should be
optimized.