What is polymer lithium-ion battery?

Polymer lithium-ion battery is a type of lithium-ion battery that uses polymers as electrolytes or key structures, and its core feature is that the morphology of the electrolyte is different from that of conventional liquid lithium-ion batteries.

Lithium ion polymer batteries are generally used in portable devices (such as mobile phones, laptops), high security applications (such as medical equipment, drones), and special form devices (such as credit card thickness devices, flexible electronic products).

The electrolyte of polymer lithium ion battery is solid or colloidal polymer material (such as gel polymer), which replaces the liquid electrolyte of traditional liquid lithium ion battery. Some types also coat polymer (such as PVDF) on the diaphragm to enhance adhesion (semi polymer) or form a gel network (all polymer), reduce the amount of liquid electrolyte and improve safety.

The use of aluminum-plastic flexible packaging film (composed of PP, Al, and nylon layers) as the outer shell is called a soft pack battery, which is lighter, thinner, and more flexible than the metal outer shell of liquid batteries. Its thickness can reach below 0.5mm and can be customized into any shape (such as trapezoid, ultra-thin card, etc.) to meet the needs of special equipment.

Safety: Due to the low leakage of electrolytes and the expandable shell that can release pressure, even in the event of a malfunction, it is usually only a gas bubble rather than an explosion.

Energy density: 10% -30% higher than traditional liquid batteries, and 20% -40% lighter in weight (without metal casing).

Cycle life: Normal use can reach over 500 times, with low self discharge rate and no memory effect.

2. Comparison dimensions with other lithium-ion batteries: Polymer lithium-ion batteries, liquid lithium-ion batteries, electrolytes, solid/colloidal polymer electrolytes, some of which contain small amounts of liquid components, liquid electrolytes (flammable), are not easy to explode, and often exhibit poor safety due to air bubbles. The shape and thickness can be ultra-thin (<1mm), and any shape can be customized with a larger thickness. The shape is fixed, the weight and capacity are the same volume, and the capacity is 10% -15% higher. The weight is 20% -40% lighter. The capacity and weight are limited by the metal shell. The voltage and combination method of a single cell can achieve higher voltage (multi-layer structure). Multiple cells need to be connected in series to achieve high voltage. The manufacturing cost is relatively high (technically complex), and the cost is relatively low. The process is mature. 

Polymer lithium-ion batteries are significantly superior to traditional liquid batteries in terms of safety, lightweight, and energy density through electrolyte and structural innovation, but at a higher cost. Its technological characteristics make it an ideal choice for high-end electronic products and emerging fields such as flexible devices, while liquid batteries still dominate the cost advantage in the mid to low end consumer battery market.