The electrolyte battery is a broad class of batteries, and almost every rechargeable battery on the market today is an electrolyte battery in one form or another. Electrolyte batteries can use acids, soluble salts, bases, gels or dry solids as the electrolyte material. The most common types on the marketplace include Li-ion, lead acid, nickel-cadmium and nickel hydride, all of which fall under the electrolyte battery banner.
So where does nanotechnology come in? Companies, such as Samsung, LG Chem, Apple and Tesla, are always looking for two ways to make batteries better – make them smaller and make them more efficient. Nanotechnology can aid with both by targeting two fundamental areas of the battery – the electrodes and the electrolyte itself.
Electrodes are a key area where researchers are trying to reduce size. The size of battery is often determined by its electrode size because the electrode is the “solid” component in many batteries (especially in those with a non-solid electrolyte). The casing of a battery needs to fit around the electrodes, so the smaller the electrodes can be made, the smaller the size of the battery.
However, even though researchers are looking to reduce the size of the electrodes, they are simultaneously looking to increase the active surface area of the electrodes to help facilitate more efficient charge/discharge cycles. One of the fundamental principles of nanomaterials is that even though they area smaller in size, they have a high specific surface area; so, they are materials which are well-suited for battery electrodes.
Many nanomaterials, from graphene, carbon nanotubes and silicon nanowires, have been tried and tested, particularly at an academic level. There are many publications coming out every year on how these nanomaterials can not only reduce the size of the battery, but also increase their efficiency and make them more flexible.
The electrolyte materials are an area of battery research that is not driven by a reduction in size. Scientists look to new electrolyte materials to increase the efficiency and safety of batteries. In many older batteries, a lot of the electrolyte materials had a habit of catching fire. Whilst this has been negated in most cases, manufacturers are always trying to find new ways of increasing the safety of batteries, especially with the high usage that electronic devices receive nowadays. Nanotechnology can be used to help both aspects, and examples of nanotechnology use in electrolytes include Al2O3, SiO2, and ZrO2 nanoparticles added into polymer electrolyte gels.
Challenges Facing Nanotech-Inspired Batteries
The battery market is notoriously difficult to break into. All the companies which use batteries are large multi-national companies and getting these companies to incorporate a new type of battery is a near-impossible task. Whilst it is true that these companies want smaller and more efficient batteries, third party battery manufacturers must go through rigorous testing before any large company will even look at any new batteries. This is usually at the manufacturers expense and can run into the millions. As such, it often prevents new battery technologies inspired by nanotechnology from reaching the commercial market.
The second is volume. Even if a company can pass all the testing and get their battery into a commercial product, most of these companies do not have the capacity to scale up their production to meet the demands of the end-user product.
The third issue is cost. Many companies want to keep their overheads, including their supply chain costs, to a minimum. Many nanomaterials are much more expensive than current materials, and to justify the increased cost in component materials, many companies would push the price of their products up – something which many companies are against in today’s competitive markets. So, until the cost of creating nanomaterials comes down, it is unlikely that many companies will be excited about using them (in a large capacity) in their products.
That being said, there are many battery manufacturers out there, such as Targray and Nohms who are implementing nanotechnology into various aspects of their batteries. Currently, nanotechnology is predominantly advancing the capability of electrolyte batteries at an academic level, but that’s not to say that it will always stay that way. There are dedicated research centres, such as the Energy Institute at the University of Birmingham, UK, and the Joint Centre for Energy Storage Research led by the Argonne National Laboratory in the US, which are aiding in the effort to implement more nanomaterials into electrolyte batteries.
Picture: Manufacture of batteries for hybrid cars.
Written by Liam Critchley.