As you know, most batteries and rechargeable batteries are composed of substances and metals that should not reach the soil and water, as they can cause serious pollution problems, however many people see spent batteries as a common waste generated in the home and not as an element that can be recycled. But the point is that, despite containing various valuable elements, the great variety of chemical compounds used in the manufacture of batteries makes them difficult to manage.
About this. A group of scientists at Nanyang Technological University (NTU) in Singapore have developed a unique method of using orange peel waste to extract and reuse the valuable metals in spent lithium-ion batteries, and then reusing them to make fully functional new batteries, thus minimizing process waste.
Source of the images: orange peel, batteries, recycling symbol.
Using this approach, this group of scientists can make use of both the spent batteries of this type, which can cause serious pollution problems by the use of different types of heavy metals, such as cadmium, lithium and zinc, and on the other hand, it is also possible to take advantage of food waste, of which millions of tons are generated annually worldwide. This encourages the development of a circular economy, where resources are kept in use as long as possible.
Conventionally, spent batteries are heat treated to melt the valuable metals and burn the rest of the components, but although this process allows the metals to be recovered and prevents the battery components from reaching the soil and water, it also emits gases that can be very toxic and dangerous. And although alternatives such as the use of acids and strong oxidizing agents to dissolve and extract the metals have been explored, the problem of secondary waste, such as spent acid solutions, continues to be generated, which pose a risk to health and the environment.
So, although the industrial processes carried out today have solved part of the problem, they generate others that are also difficult to solve, since the use of strong chemicals on an industrial scale also generates a large amount of secondary pollutants, in addition to the fact that these methods consume a lot of energy. This demonstrates the urgent need to address the problem through environmentally friendly technological solutions.
A sustainable approach
The NTU team of scientists demonstrated that the use of dried and ground orange peels, together with citric acid, which is a weak acid naturally contained in fruits, can achieve the same goal as using stronger and more dangerous substances.
According to the sources, it was demonstrated through laboratory tests, that it is possible to successfully extract 90% of metals such as cobalt, lithium, nickel and manganese contained in spent lithium-ion rechargeable batteries, an effectiveness comparable to conventional methods.
It seems that the key is the cellulose contained in the orange peel, which is converted into sugars under the heat applied during the extraction process, and these sugars improve the process of extracting the waste from the batteries.
With the recovered metals, new rechargeable lithium-ion batteries were assembled, which showed a similar capacity to the new ones, but developments continue to be made to optimize the performance of the charge-discharge cycle in these batteries of recovered materials. On the other side, secondary waste generated by this method is not considered toxic or dangerous, so it is a method that can be considered ecological and rational.
This would allow an environmentally friendly technology very feasible to be implemented industrially in the recycling of spent rechargeable batteries.
In addition, it could drive an urban mining process to extract valuable metals from different types of discarded electronic devices, which could be a very valuable option to consider for some countries with scarce mineral resources of this type, or even very important to consider in order to decrease the exploitation of metallic minerals from the soil to produce virgin raw material.
Thus, with methods like this, we would be attacking different problems at the same time, directly the problem of resource depletion by keeping these valuable metals in use longer, and on the other hand, also the problems that generate the accumulation of electronic waste and household food waste.
Well friends, referring to the topic is important to create conscience, because what today we see as a simple battery that does not serve, inside it has valuable but heavy metals like nickel and cadmium, which although they served their purpose are still usable, otherwise they become potential sources of pollution.
Thank you for reading me. Until the next post!
This post has been published previously in my other blog.