I. Distinguishing by advantages
1. The original liquid electrolyte was replaced with a solid electrolyte.
2. Lithium-ion anode materials were used instead of carbon anode materials.
3. Lightweight
4. Ultra-thin
5. Flexible shape: Can be made into different shapes to meet different needs.
6. Improved safety: It remains stable even when overcharged, and because the electrolyte is solid, the probability of leakage is very low.
FPV drone battery image
II. From the perspective of packaging and internal composition
1. Sheet-like: If it's wrapped in stickers, try gently prying it back and forth a few times with both hands. If there's a plastic frame around the edge, it's likely a regular lithium-ion battery, not a polymer. Peel off the sticker to expose the battery cell. If the edge is a rectangular block with right angles, it's probably a regular lithium-ion battery. If the edge is a curved cell with gaps in the metal casing, it's likely a polymer battery. Polymer batteries can be further disassembled to reveal a vacuum-sealed aluminum foil sheet. Regular lithium-ion batteries only show a square metal casing cell, which cannot be disassembled by hand.
2. Barrel-shaped, typically with a higher lithium-ion content and lower polymer content. Polymers are mostly flat.
III. From the perspective of product attributes
Lithium polymer batteries (Li-polymer, also known as polymer lithium batteries): These are a type of lithium-ion battery, but compared to liquid lithium batteries (Li-ion), they offer numerous advantages such as higher energy density, smaller size, ultra-thin design, lighter weight, and higher safety, making them a new type of battery. In terms of shape, lithium polymer batteries are ultra-thin and can be manufactured into any shape and capacity to meet the needs of various products. The minimum thickness achievable for these batteries is 0.5mm. Their nominal voltage is the same as Li-ion batteries, 3.7 volts, and they have no memory effect. Polymer batteries are made by mixing solvents and binders with the positive and negative electrode active materials, respectively. After high-speed stirring to achieve uniformity, a slurry-like positive and negative electrode material is formed. The electrolyte is solid.
Precautions: Disassembly may result in a fire or even an explosion. Furthermore, the polymer's electrolyte reacts with moisture in the air to form highly toxic hydrofluoric acid (HF).
The safety of power banks has always been a concern for consumers. How to distinguish between genuine and counterfeit power banks is a matter of great interest to the public. Below, Huolang Electronics will teach you how to distinguish between genuine and counterfeit power banks by looking at the differences between polymer cells and lithium-ion cells.
When purchasing a power bank, you'll usually see the type of battery cell used in the product description. Currently, the most common battery cells on the market are basically divided into three types: polymer cells, lithium-ion cells, and lithium iron phosphate cells. Among these, lithium-ion cells are the most widely used, being both inexpensive and of good quality.
Because polymer batteries are safer than lithium-ion batteries and cheaper than lithium iron phosphate batteries, many users prefer polymer batteries. Currently, many power banks on the market claim to use polymer batteries, but this is not the case. Most of these products actually use pouch lithium-ion batteries. So, what exactly is the difference between lithium-ion and polymer batteries?
We usually conduct teardown tests on many power banks, including those with 18650 cells and some with polymer cells. Today, we randomly chose to disassemble a polymer cell to discuss the differences between polymer cells and lithium-ion cells from an internal structure perspective.
It looks so real that it's hard to tell the difference.
In the classic novel *Journey to the West*, there's a story about the true and false Monkey Kings. The Six-Eared Macaque, skilled in disguise, impersonated Sun Wukong, fooling all the gods and Buddhas, until finally, the Buddha himself revealed the truth. For polymer battery cells, soft-pack lithium-ion batteries are practically another Six-Eared Macaque; they are virtually indistinguishable from each other in appearance.
The body is relatively thin
The biggest difference between polymer cells and ordinary 18650 cells lies in their appearance. Ordinary 18650 cells are similar in shape to AA batteries, while polymer cells have better plasticity in appearance and can be made into any area and any shape. Theoretically, the thinnest thickness can be as low as 0.5mm, making the power bank look thinner and lighter, thus improving portability.
Internal structure of fake polymer battery cells
We cut open the outer film of the prepared battery cell. The film was quite tough, silver in color, and emitted a strong chemical smell. Clearly, this "polymer battery cell" is actually a pouch lithium-ion battery cell. Let's examine the details to understand why we made this judgment.
