The difference between polymer lithium batteries and 18650 lithium batteries.
The thinner the polymer battery, the better the production, and the thicker the lithium battery, the better the production, which allows lithium batteries to broaden their application fields. Let's take a look at the advantages and disadvantages of polymer lithium batteries and related knowledge below!
The difference between lithium-ion batteries and polymer lithium batteries
1. The raw materials are different, and the raw material for lithium-ion batteries is electrolyte (liquid or colloid); The raw materials for polymer lithium batteries are electrolytes, including polymer electrolytes (solid or colloidal) and organic electrolytes.
2. In terms of safety,
lithium-ion batteries can easily explode in high-temperature and high-pressure environments; Polymer lithium batteries use aluminum-plastic film as the shell, and when organic electrolytes are used internally, they will not explode even if the liquid is very hot.
3. Different in shaping, polymer batteries can achieve thinning, arbitrary surface area, and arbitrary shape because their electrolytes can be solid or colloidal rather than liquid, while lithium batteries use electrolytes and require a sturdy outer shell as secondary packaging to contain the electrolyte.
4. The voltage of battery cells is different because polymer batteries use polymer materials and can be assembled into multiple layers to achieve high voltage, while lithium battery cells have a nominal capacity of 3.6V. To achieve high voltage in practical applications, multiple battery cells need to be connected in series to form a high-voltage operating platform with negative voltage.
5. The production process is different, the thinner the polymer battery, the better the production, and the thicker the lithium battery, the better the production. This allows lithium batteries to broaden their application fields.
6. The capacity of polymer batteries has not been significantly improved, and there is still some reduction compared to lithium batteries with standardized capacity.
Advantages of polymer lithium batteries
1. Good safety performance. Polymer lithium batteries use aluminum-plastic flexible packaging in their structure, which is different from the metal shell of liquid batteries. Once a safety hazard occurs, lithium-ion batteries can easily explode, while polymer batteries will only inflate and at most burn.
2. Small thickness can make it thinner, ultra-thin, with a thickness of less than 1mm, and can be assembled into credit cards. There is a technical bottleneck in achieving a thickness of less than 3.6mm for ordinary liquid lithium batteries, while 18650 batteries have a standardized volume.
3. Lightweight and high-capacity, batteries using polymer electrolytes do not require a metal shell as a protective outer packaging. Therefore, when the capacity is the same, they are 40% lighter than steel shell lithium batteries and 20% lighter than aluminum shell batteries. When the volume is generally large, the capacity of polymer batteries is larger, about 30% higher.
4. The shape can be customized, and the thickness of polymer batteries can be added or reduced according to practical needs. For example, a famous brand's new laptop uses trapezoidal polymer batteries to fully utilize the internal space.
Defects of polymer lithium batteries
1. The main reason is that the cost is relatively high, as it can be planned according to customer needs, and the R&D cost here needs to be included. Moreover, due to the varied shapes and diverse types, various fixtures and jigs are used in the production process to correct and standardize the parts, which also increases the cost accordingly.
2. The universality of polymer batteries themselves is poor, which is also due to sensitive planning. Often, in order to achieve such a 1mm difference, it is necessary to plan a new product for customers from scratch.
3. Just if it breaks down, it will be completely useless, and it is necessary to protect the circuit control. Overcharging or overdischarging can damage the reversibility of the chemical substances inside the battery, seriously affecting its lifespan.
4. The lifespan is shorter than
18650 lithium battery due to the use of different planning and materials. Some have liquid inside, while others are dry or colloidal, and their performance is not as good as cylindrical batteries of 18650 during high current discharge.
