A battery is composed of an anode, a cathode, and an electrolyte. The anode (the negative terminal) supplies electrons that flow to the cathode (the positive terminal) through an external electric circuit. A battery basically converts chemical energy into electrical energy and it can be primary or non-rechargeable or secondary or rechargeable battery.
Alkaline batteries like zinc carbon and silver oxide batteries are non-rechargeable or primary, while lithium and lead-acid batteries are chargeable or secondary batteries. Batteries used in the automotive sector are secondary or rechargeable batteries.
Presently, the automotive battery market is dominated by Li-ion batteries, although Ni-MH batteries are also in use. Li-ion batteries are considered superior to Ni-MH batteries in terms of weight, ‘memory-effect’, and the speed at which they can be charged or discharged. Ni-MH batteries are less expensive, but a bit larger and heavier than Li-ion batteries.
Since weight is a major consideration when it comes to electric and hybrid cars, Li-ion batteries are preferred by the automotive companies. However, Li-ion batteries also have some limitations, which is fuelling the search for alternatives or the next-generation batteries. Some of these batteries that can have huge impact on the automotive sector in the future are grapheme batteries, solid state batteries, Zinc-air batteries, and flow batteries which include redox, hybrid, and Zn-Br (Zinc-Bromine) batteries.
For example, Zinc-air batteries are better than Li-ion batteries in terms of safety. They can store as much energy as Li-ion batteries and at the same time, can be cheaper, smaller, and lighter. However, the zinc-air technology is not rechargeable. To overcome this drawback, researchers are currently exploring the possibility of making the zinc anode regenerate when oxygen is released. If a breakthrough is achieved in the future, the technology can help automakers to manufacture safer and lighter cars.
Another battery that is generating much interest in the automotive sector is the solid state battery. Solid state batteries use cells made of solid and dry conductive material, instead of liquid electrolytes. This makes them safer and less likely to catch fire than Li-ion batteries. Solid state batteries also charge faster than Li-ion batteries.
In Li-ion batteries, heat is generated when the liquid electrolyte moves. If the battery is subjected to excess pressure or if it gets damaged, there is a risk of the liquid electrolyte reacting and generating heat. At times, it can also ignite. Solid state batteries do no suffer from this safety issue.
Yet another battery that is being investigated for its potential to be used in automobiles is the graphene battery. This battery charges really fast and is also environmental-friendly. Tesla is rumoured to be exploring graphene to power their electric cars. Other than fast charging, grapheme batteries are being explored to provide a better battery life and performance.
Apart from these next-generation batteries, scientists and researchers across the globe are also concentrating on ultracapacitors, a device that can store a large amount of electrical energy or charge. In the future, these devices might emerge as an alternative to batteries. This technology is currently lagging behind batteries in certain areas. But, advancements in technology may improve the efficiency of ultracapacitors in the coming days.
So, in the coming years, we can expect to witness more advancements in the next-generation batteries. However, Li-ion batteries are currently dominating the market and are likely to do so in the near future. As of now, these new generation batteries are not posing any threat to the market dominance of Li-ion batteries.