Ultra-thin lithium batteries are suitable for thin and light products such as smart badges and adult products. However, when the thickness is close to 1 mm or less, capacity, peak power, durability, safety and cost must be balanced.
The following is general battery engineering information. Specific designs should be independently verified.
1. Energy density and total capacity:
The active material space is limited and the capacity is usually small; the increased proportion of packaging materials and current collectors may also reduce the mass energy density.
- Volume limit:When the battery is compressed to an extremely thin thickness (such as less than 1 mm), the volume of its internal active materials (positive and negative electrode materials) is very limited, soThe total capacity of the battery is usually smaller, mainly suitable for low-power devices.
- Energy density:Although ultra-thin batteries can be made very light, due to the relative increase in the proportion of packaging materials (such as aluminum-plastic films) and current collectors in the battery, theirmass energy densitySometimes it's a sub-par thick battery.
2. Mechanical strength and durability:
Thin aluminum-plastic films are more susceptible to puncture, folding or squeezing; poor sealing will absorb moisture, bulge or fail.
- Vulnerability:The encapsulation layer (aluminum-plastic film) is very thin. Compared with metal-cased batteries, ultra-thin soft-pack batteries are more susceptible toPhysical puncture, compression or squeezingDamage may result in leakage or internal short circuit.
- Package reliability:It is difficult to seal the extremely thin edges. If the sealing is not tight, the electrolyte can easily absorb moisture in the air, causing the battery to bulge or fail.
3. Charge and discharge performance:
The thinning of the pole pieces and tabs will increase the DC internal resistance (DCR), and voltage drops may occur during strong vibration, pulse load or long-distance wireless transmission.
