Electrolytes Enhance Implant Battery: Over the past few decades, battery research has mostly focus on rechargeable lithium-ion batteries. Those batteries are us in everything from electric vehicles to portable electronics. Therefore. Lithium-ion batteries have improv dramatically in terms of affordability and capacity.
non-rechargeable batteries saw little improvement during that time. In fact, this type of battery has an important role in many uses. Such as implant medical devices such as pacemakers. Now. Researchers at the Massachusetts Institute of Technology (MIT). Have found a way to increase the energy density of these non-rechargeable batteries.
They say the new way could allow up to a 50 percent increase in service life.
In addition, it is possible to reduce size and weight accordingly for a given amount of power or energy capacity. While at the same time increasing safety at little or no increase in cost. The new findings involve replacing conventionally inactive battery electrolytes with active ingredients for energy delivery.
The researchers published their findings in the Proceedings of the National Academy of Sciences. In a paper by Postdoctoral Fellow at MIT Haining Gao. Graduate student Alejandro Sevilla. Mechanical engineering professor Betar Gallant, and four others at MIT and Caltech.
Save more energy
Gallant said that replacing batteries in pacemakers or other medical implants requires a surgical procedure. Therefore, any increase in battery life can have a significant impact on the patient’s quality of life. Primary batteries are us for such important applications because they can provide about three times more energy for a given size and weight than rechargeable batteries. That difference in capacity. Said Gao. Makes primary batteries “essential for applications where charging is not possible or impractical.” This new material works at human body temperature, making it suitable for medical implants.
In addition to implantable devices. With further development to make batteries operate efficiently at cooler temperatures. Deployments may also include sensors in tracking devices for shipments. For example. To ensure that the temperature and humidity requirements for the delivery of food or medicine are properly maintain during the delivery process. Alternatively. Its application may also be used in remotely operated aerial or underwater vehicles that must remain on standby for long periods of deployment.
Pacemaker batteries usually last from 5-10 years, and even less if they require high voltage functions such as defibrillation. But for such a battery the technology is considered mature, and “there haven’t been any major innovations in fundamental cell chemistry in the last 40 years.”
The key to the research team’s innovation is a new type of electrolyte; it is the material that lies between the two electrical poles of a battery, namely the cathode and the anode, and allows charge carriers to pass from one side to the other.
Using a new liquid fluorinated compound, the research team discovered they could combine several cathode and electrolyte functions in a single compound, called a catholyte. This makes it possible to save a lot of weight on regular primary batteries.
In fact, there are materials other than these new compounds that could theoretically function in a similar catholyte role in high-capacity batteries. However, according to Gallant, the material has a lower built-in voltage that is incompatible with the rest of the materials in conventional pacemaker batteries, the type known as a CFx.
Stable shelf life
Since the overall output of the battery cannot be more than two electrode materials lower, the extra capacity will be wasted due to voltage mismatch. But with this new material, says Gallant, “one of the main advantages of the fluorinated liquid we developed is that the voltage is very much in sync with the CFx.” In conventional CFx batteries, the liquid electrolyte is very important because it allows charged particles to pass from one electrode to another. However, “those electrolytes aren’t actually chemically active, so they’re basically dead weight.
This means that about 50 percent of the main components of a battery, especially electrolytes, are inactive materials. However, in the new design with fluorinated catholyte materials, the amount of dead weight can be reduced by about 20 percent. The new cells also provide increased safety over other proposed chemical types. Preliminary testing has also shown a stable shelf life of more than one year, an important characteristic for primary batteries.