Which is better, polymer battery or lithium battery? What is the difference between the two
Issuing time:2020-07-20 09:23
The concept of lithium battery is used very frequently. With a little attention, we will find that there are three distinctions between broad sense, narrow sense and narrow sense when using this concept. Lithium batteries in a broad sense include lithium primary batteries and lithium-ion batteries; because lithium-ion batteries are more widely used than lithium primary batteries, lithium batteries usually refer to lithium-ion batteries in a narrower sense; there are two types of lithium-ion batteries: Polymer lithium-ion batteries and liquid lithium-ion batteries are liquid lithium-ion batteries with greater mass and more applications, so the narrow understanding of lithium batteries refers to liquid lithium-ion batteries, and polymer lithium-ion batteries are also called lithium polymers. Batteries are commonly referred to as polymer batteries. If you compare the difference between lithium polymer batteries and lithium batteries in a broad and narrow sense, then the only thing is the relationship between species and genus concepts. Lithium polymer batteries are included in lithium batteries. Therefore, what is of more significance is the comparison on the narrow level: that is, the comparison between polymer batteries and liquid lithium-ion batteries. Based on this, the following uses lithium batteries to refer to liquid lithium-ion batteries.
1. The fundamental difference is the raw material
This is the total source of the different performances of the two. Polymer battery refers to the use of polymer materials in at least one of the three major components of the positive electrode, negative electrode or electrolyte. Macromolecule means large molecular weight, and the corresponding concept is small molecule. Macromolecule has high strength, high toughness and high elasticity. The polymer materials currently developed for polymer batteries are mainly used for positive electrodes and electrolytes. ①In addition to the inorganic compound of the lithium battery, the positive electrode material of the polymer battery can also use the conductive polymer; ②The electrolyte of the polymer battery includes the polymer electrolyte (solid or colloidal) and the organic electrolyte, and the lithium battery uses the electrolyte (Liquid or gel)
2, the difference between shaping
The polymer battery can be thinner, any area and any shape because its electrolyte can be solid or colloidal rather than liquid. Lithium batteries use electrolyte, which requires a solid casing as a secondary package to contain the electrolyte. . Therefore, this also makes the lithium battery add some weight.
Most of the current polymer batteries are soft pack batteries, using aluminum plastic film as the outer shell. When the organic electrolyte is used inside, the liquid will not explode even if the liquid is hot, because the aluminum plastic film polymer battery adopts solid or colloidal state without leakage, but Naturally rupture. But nothing is absolute. If the instantaneous current is large enough and a short circuit occurs, it is not impossible for the battery to spontaneously ignite or burst. The safety accidents of mobile phones and tablet computers are mostly caused by this situation.
4, cell 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 cell is 3.6V. If you want to achieve high voltage in actual use, you need to combine multiple The batteries are connected in series to form an ideal high-voltage working platform.
If you compare polymer batteries and lithium batteries with the above characteristics, the conclusion is certain. However, the application of lithium batteries still dominates the market. This shows that lithium batteries also have relative advantages. We will continue to compare.
The ionic conductivity of the solid electrolyte of polymer battery is low. At present, some additives are mainly added to make it a gel electrolyte to improve the conductivity. This only increases the ionic conductivity, unlike the conductivity of the lithium battery to maintain a stable value without being affected by the quality of the auxiliary materials.
The capacity of polymer batteries has not been effectively improved, and it has been reduced compared with standard capacity lithium batteries.
7, manufacturing process
The thinner the polymer battery, the better the production, and the thicker the lithium battery, the better the production, which makes the application of lithium batteries more expandable.
This is a key factor in determining the market capacity of the two. At present, the price of polymer batteries on the market is generally higher than that of lithium batteries, which affects the market capacity of the two. The ratio of the former to the latter is 1:9.
It is difficult to say absolutely which polymer battery or lithium battery is better. They have their own advantages and disadvantages. If you have to say a conclusion, polymer batteries are more promising for small applications, while lithium batteries are more promising for large applications. If polymer batteries are The ability to break through the limitations of price and design may represent the development trend of batteries, because its environmental protection and safety are more in line with the trend.