Scientists at Edith Cowan University in Australia have come to conclusions that may have big implications for the electric car industry by demonstrating the potential of zinc-air batteries as an alternative to lithium-ion. The biggest advantage is that they offer much more density, that is, they are capable of storing more energy in less space, offering high levels of efficiency and autonomy.
The batteries referred to in the study are composed of a negative zinc electrode and a positive air electrode. Its main disadvantage is that the air electrode can degrade over time, reducing battery performance and autonomy. On the positive side, it has benefits such as reduced costs and lower environmental impact, compared to lithium-ion batteries, currently the most used in electric mobility.
How did specialists remedy the shortcomings of zinc-air batteries, positioning them as a viable option? According to the study, the improvements were achieved through a redesign, and through new materials such as carbon, iron and cobalt-based minerals.
Advantages and disadvantages of zinc-air batteries
“The batteries rechargeable zinc-air are increasingly attractive due to their low cost, environmental friendliness, theoretical high energy density, and inherent safety,” said the study’s lead author, Dr. Muhammad Rizwan Azhar.
In theory, this type of battery has all the characteristics necessary to meet the demand that currently exists, as the adoption of electric mobility increases throughout the world. It offers more autonomy, that is, it can travel further on a single charge, at lower prices —making cars cheaper— and more sustainable.
“The new design has been so efficient that it has suppressed the internal resistance of the batteries and their voltage has been close to the theoretical one, which gives rise to a high maximum power density and long-term stability”, indicated Dr. Azhar .
Beyond the advantages indicated, zinc-air batteries have limitations and face significant challenges before their large-scale production. The main challenge is to avoid degradation of the air electrode. There is also the problem of its loss of efficiency at low temperatures.
Characteristics of lithium-ion batteries, the industry standard
Beyond zinc-air batteries, there is currently a standard: variants that use lithium salt. Most mobile devices draw power from that component, including smartphones, smartwatches, tablets, and laptops. Electric cars use them, too, and there’s even the possibility of a future generation of planes with that feature.
As with any other technology, Lithium-ion batteries have advantages and disadvantages. Among the first, its density, resistance to discharge and the ability to operate in a high number of charge and discharge cycles stand out. Among the latter, they are sensitive to temperature changes, their long processes and production costs.
Zinc-air, a possible solution?
The development of electric vehicles, as well as the activity of various industrial sectors, imposes the search for alternatives to lithium-ion batteries. The objective is to obtain options that are easier to produce, with less use of raw materials and with greater density.
The study released by the Australian institution shows a certain level of enthusiasm regarding the potential of zinc-air batteries to revolutionize electric mobility. A point in favor of the proposal is the wide availability of the resource. “Because of its abundance in countries like Australia, and the ubiquity of air, what we are proposing is a very viable and reliable solution,” Azhar explained.
However, it is important to note that the technology is still in its early stages, and it is important to take these announcements with a grain of salt. Although this is not necessarily the case, it is common for laboratories to make big promises in order to attract investors and improve their reputation, but many of these projects never reach the full-scale production stage.