Polymer Lithium Battery
High energy density enables polymer lithium batteries to power devices that require compact, long-lasting energy sources. This translates into a longer operating lifespan for electronic products, reducing replacement costs and electronic waste while aligning with sustainability goals.
Unlike Li-ion cells that use liquid electrolytes, polymer lithium batteries utilize dry solid, gel-like electrolytes. They also have superior safety characteristics, which makes them an excellent choice for critical applications.
High Energy Density
Lithium polymer batteries have a higher energy density than lithium-ion cells, meaning they can hold more power in a smaller package. The increased energy density opens up more battery applications that can benefit from a long run time, such as forklifts and power tools.
However, this increased energy efficiency comes with a price: lithium-polymer batteries are more expensive than lithium-ion batteries. The higher cost is due to the complexities involved in producing these batteries.
For polymer lithium batteries, the separator and electrolyte are made of a solid instead of liquid. This means the battery can be designed with a smaller volume and more flexible design. This allows for better battery performance, especially when it comes to cycling.
Polymer lithium batteries use a positive and negative electrode with a dry solid porous chemical or gel-like electrolyte, instead of a liquid. This improves safety by eliminating the polymer lithium battery risk of leaking electrolytes that can cause thermal runaway.
In order to attain high energy-density SSLIBs, it is critical that a good cathode/electrolyte interface be achieved. In this regard, Guo et al. developed an interpenetrated network of ion-conductive PEO and branched acrylate. This material is characterized by a low crystallinity and by its ionic conductivity at elevated temperatures, which enables Li+ migration in the polymer matrix. It also exhibits a favorable mechanical strength to suppress the growth of Li dendrites.
Long Cycle Life
Lithium polymer batteries have longer cycle life than lithium ion batteries. In fact, the battery can be used over 500 times after a complete discharge. The number of cycles varies by pack design, chemistry and temperature conditions. Pouch cell Lithium Polymer with a cobalt aluminum oxide chemistry may only reach 100 cycles, while high-quality cylindrical Lithium Iron Phosphate cells can exceed 20,000 cycles.
Both types of lithium batteries can be used in a variety of consumer and industrial applications. They can power phones, laptops, digital cameras and car batteries. They can also be used in UPS, electric vehicles and solar energy storage systems. Lithium polymer batteries can even be used in the medical industry, such as in insulin pumps and blood pressure devices.
Most consumers want their batteries to last as long as possible. To maximize capacity, they tend to charge them to the maximum voltage of 4.20V/cell. However, this can damage the battery and shorten its lifespan. For this reason, it’s best to use lithium batteries at lower charges. Moreover, it’s important to keep batteries out of extreme temperatures and avoid dwelling in a high state-of-charge for long periods of time. These factors can cause the battery to deteriorate quickly, reducing its cycling life. Nevertheless, with proper maintenance and storage, battery life can be extended significantly.
Superior Safety Performance
Despite its many advantages, lithium-ion battery is prone to heat related failures and thermal runaway. This problem is usually solved by the use of a BMS (Battery Management System) that controls overheating and internal short circuits, but this impedes on the speed at which the battery can be charged and discharged.
The problem is caused by the lithium metal reacting with the liquid electrolyte, which generates irregular metal deposits known as Li dendrites. This can cause the battery to explode or fire, which is why it is crucial to limit the amount of lithium in the batteries.
To overcome this problem, scientists have developed solid polymer electrolytes (SPEs). Solar Lithium Battery They act as separators and electrolytes in solid-state configurations. This allows for the use of a low-pressure and high-temperature operating temperature, which is much safer than the liquid electrolyte used in lithium-ion batteries.
The SPE is made of a polymer host with a large number of electron donor groups. When an electric field is applied, the cations of the Li metal are solvated in these sites, and they then hop from one to another – this process is called ion hopping. It is facilitated either by segmental motion of the polymer chains or by strong Lewis-type acid-base interactions between the cations and the coordinating groups. The hopping of the ions helps to prevent lithium from forming dendrites, as well as promoting faster charging and discharging times.
More Versatile
Lithium polymer batteries offer more versatility than lithium-ion ones. They’re often found powering smart wearables and other gadgets that require extremely compact batteries with a high energy density and long cycle life. They can also be used in vehicles where a smaller battery is required without sacrificing the performance needed to power all of the car’s functions and features.
This battery technology is able to achieve this by using dry solid, gel-like electrolytes instead of liquid. This allows the batteries to be constructed in a way that is more compact and flexible than lithium-ion cells, with a lower chance of leaking electrolytes leading to thermal runaway. Lithium polymer cells are also a bit safer than lithium-ion ones, as they’re less likely to explode in case they get punctured or stressed.
To develop these solid electrolytes, a wide range of versatile polymers were explored. The goal was to find a material that could provide a safe interface with lithium metal, ensure high ionic conductivity and maintain a good mechanical stability and flexibility. Polymers such as PEO and PVDF were used to create these solid electrolytes, and after swelling in the appropriate plasticizers they were able to meet all of the requirements for this battery technology.
Lithium-ion and lithium-polymer batteries are two of the most popular rechargeable battery types on the market, each offering unique strengths and applications. It is important to note, however, that they are hardly interchangeable, and choosing which type is right for your device depends on whether you prioritize high power density, utmost safety, cost-effectiveness or flexibility.
