Which is better, polymer or lithium battery? What are the differences?

Which is better between polymer and lithium battery? What are the differences? Lithium battery refers to lithium ion secondary rechargeable battery. From the appearance, there are three types of cylindrical steel shell, square aluminum shell and soft package. The soft package is polymer. It can be seen that the polymer is actually a polymer lithium battery, which is a kind of lithium battery. In this article, lithium batteries specifically refer to cylindrical lithium batteries. So even better, polymer and lithium batteries are actually talking about polymer and cylindrical lithium batteries. Let us find out the answer by comparing the following aspects. 1. Material Lithium batteries use liquid electrolytes, while polymer batteries use gel electrolytes and solid electrolytes. In fact, domestic polymers cannot really be called polymers, nor are they really solids. Rather, there is no liquid flowing. This is a digression, so I won't talk about it. 2. Packaging method and appearance This polymer is encapsulated in aluminum-plastic film and can be made into any shape, thick or thin, large or small. The lithium battery is packaged in a steel case. The most common model is 18650, with a diameter of 18mm and a height of 65mm. The shape is fixed. You cannot change it. 3. There is no liquid flow and no leakage in the safety polymer. When the internal temperature is high, the aluminum plastic film shell will only expand or bulge, and will not explode. It is safer than lithium batteries. Of course, this is not absolute. If the instantaneous current of the polymer battery is large enough to be short-circuited, the battery will spontaneously ignite or explode. Samsung’s battery exploded a few years ago, and this year Lenovo’s recall of laptops due to battery failures. 4. Energy density The average 18650 battery capacity can reach about 2200mAh, the energy density is about 500Wh/L, and the energy density of polymer batteries can be close to 600Wh/L during mass production. 5. Battery voltage Because the polymer battery uses polymer materials, it can be made into a multilayer combination in the battery to achieve high voltage, and the nominal capacity of the lithium battery is 3.6v. In order to achieve high voltage in practical applications, multiple batteries must be connected in series to form an ideal high-voltage working platform. Polymer battery or lithium battery is better. Therefore, polymer seems to have more advantages than lithium battery. But what exists is reasonable, and there must be something irreplaceable between them. Let us look at the last item: 6, polymers with the same energy price are usually more expensive than lithium batteries. But you cannot say that this is a disadvantage of polymers. Polymers are increasingly being used to replace lithium batteries in consumer electronic products, such as laptop computers and mobile power supplies. In closed cells, polymers are required to achieve maximum energy density. Due to the fixed shape of the lithium battery, it cannot be customized according to the customer's design. But polymer batteries do not have a uniform size, which in turn is a disadvantage in some respects. The battery used in Tesla cars is composed of more than 7000 18650 units connected in series and parallel, plus a power control system. It seems that polymer or lithium battery is better, which is better, still depends on the specific situation, can not give a single conclusion. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: 14 practical tips to extend the battery life of mobile phones