The difference between lithium-ion battery packs and polymer lithium-ion batteries:
The concept of lithium-ion batteries encompasses both lithium-ion batteries and lithium polymer batteries. If we compare the differences between lithium polymer batteries and lithium-ion battery packs in a broad and narrower sense, the only distinction is that they are species and genus concepts; lithium polymer batteries are subsumed under the category of lithium-ion batteries. Lithium-ion battery packs generally refer to aluminum-cased batteries with liquid electrolytes and aluminum casings. Lithium polymer batteries refer to lithium-ion batteries with all-solid-state or gel-based electrolytes. They typically use aluminum-plastic composite films as packaging materials.
①Raw materials
Polymer lithium-ion batteries refer to batteries in which at least one of the three main components—the positive electrode, the negative electrode, or the electrolyte—uses a polymer material. "Polymer" refers to a large molecular weight, as opposed to small molecules. Polymers possess high strength, high toughness, and high elasticity. Currently, polymer materials for polymer batteries are primarily used in the positive electrode and electrolyte.
② Differences in shaping
Polymer lithium-ion batteries can be made thin, of any size, and of any shape because their electrolyte can be solid or gel-like rather than liquid. Lithium-ion battery packs, on the other hand, use electrolytes and require a robust outer casing as a secondary packaging to contain the electrolyte. This adds to the weight of lithium-ion batteries.
③ Safety
Most polymer batteries currently available are pouch lithium-ion batteries, using aluminum-plastic film as the outer casing. When organic electrolyte is used inside, they will not explode even when the liquid is very hot, because aluminum-plastic film polymer batteries are solid or gel-like and do not leak; they simply break naturally.
Which is better, lithium-ion battery packs or polymer lithium-ion batteries?
Lithium polymer batteries possess numerous distinct advantages, including high energy density, miniaturization, ultra-thinness, lightweight design, high safety, and low cost, making them a novel type of battery. In terms of shape, lithium polymer batteries are ultra-thin, allowing them to be manufactured into any shape and capacity to meet the requirements of various products. The minimum thickness achievable for this type of battery is as low as 0.5 mm.
In polymer lithium-ion batteries, the electrolyte plays a dual role as both a separator and an electrolyte solution: on the one hand, it acts like a separator to isolate the positive and negative electrode materials, preventing self-discharge and short circuits within the battery; on the other hand, it acts like an electrolyte to conduct lithium ions between the positive and negative electrodes. Polymer electrolytes not only possess excellent conductivity but also exhibit the unique properties of polymer materials, such as light weight, good elasticity, and ease of film formation, aligning with the development trend of lightweight, safe, efficient, and environmentally friendly chemical power sources.
