The fact that efficient and rechargeable lithium-ion (Li-ion) batteries are used in laptops, smartphones, and even electric cars is well known.
Regrettably, lithium has become a rather limited resource, and hence it would be difficult to meet the world’s increasing demand for batteries that are comparatively cheap. Given this scenario, scientists are seeking alternative solutions to Li-ion batteries.
One potential alternative is to develop sodium-ion batteries, in which sodium metal is used in the place of lithium. Sodium occurs abundantly in seawater, and therefore, it can be easily obtained.
The Next Big Battery Success
While the Na-ion battery is still being developed, scientists are exploring ways to reduce its charging time, improve its service life, and create batteries that can supply sufficient amounts of watts, informed Dorthe Bomholdt Ravnsbæk, a research leader from the Department of Physics, Chemistry and Pharmacy at the University of Southern Denmark.
Along with her research team, Ravnsbæk is focused on creating novel and more improved rechargeable batteries that can substitute Li-ion batteries that are currently being used extensively.
But to make Na-ion batteries as an alternative solution to lithium batteries, more improved electrode materials have to be developed. This is something Ravnsbæk and collaborators from the Massachusetts Institute of Technology, USA, and the University of Technology have observed in their latest study. The study was published in the ACS Applied Energy Materials journal.
However, before looking into the study details, it would be better to take a closer look at the Na-ion battery and its ability to become the next major breakthrough in the battery segment.
The Moral Qualms
One evident benefit is that sodium is a resource that is readily available and occurs abundantly in seawater. By contrast, lithium is known to be a rather limited resource and is extracted only in certain locations across the world, Dorthe Bomholdt Ravnsbæk explained.
Another benefit is that cobalt is not needed for Na-ion batteries but the same is required in the case of Li-ion batteries. A majority of the cobalt currently used for producing Li-ion batteries is extracted in the Democratic Republic of Congo, where child labor, disorganized mining, and rebellion create moral qualms and uncertainty with respect to the cobalt trade of the nation.
Yet another advantage is that Na-ion batteries can be developed at the same factories where Li-ion batteries are currently being made.
Manganese Makes All the Difference
In their latest research, Dorthe Bomholdt Ravnsbæk and her collaborators analyzed a new kind of electrode material based on phosphorus, manganese, and iron. The best thing about this electrode material is that manganese is also added to it. This element provides a higher voltage (volts) to the battery and also boosts its capacity. In addition, it can potentially supply more watts.
This is because the atomic-level transformations that take place during the charge and discharge cycle are considerably altered by the presence of manganese.
Although analogous effects have been observed in the case of Li-ion batteries, it is quite surprising that the same effect is also retained in the Na-ion battery. This is because the electrode-Na-ion interaction is extremely different from the interaction of Li-ions, added Dorthe Bomholdt Ravnsbæk.
China is Testing
Dorthe Bomholdt Ravnsbæk will not attempt to estimate the time it will take for seawater-based Na-ion batteries to be incorporated in electric cars and phones, because certain challenges still exist that need to be overcome.
One of the major challenges is that tiny Na-ion batteries cannot be developed easily. However, huge batteries are also useful, for instance, when it comes to preserving solar energy or wind energy.
Therefore, a large 100 kWh Na-ion battery was launched in 2019 to be investigated by Chinese researchers at the Yangtze River Delta Physics Research Center. Containing over 600 connected Na-ion battery cells, the huge battery delivers power to the building that accommodates the Yangtze River Delta Physics Research Center. Excess current from the main grid is stored in this giant battery.