ELECTRIC vehicles (EV) are becoming increasingly popular worldwide as people become increasingly concerned about climate change.
This was prompted by a statement issued by Tesla CEO, Elon Musk, that electricity consumption would double if all cars switched to electric vehicles.
This need aligns with the Malaysian government's commitment to outline net-zero carbon emissions as early as 2050. The electric car battery, known as BKE, due to its environment-friendly nature can operate at a cheaper cost for a long duration.
It has led to rising demand for BKE production around the world. BKE is a battery utilised to drive electric motors for electric cars or hybrid electric cars. Meanwhile, these batteries are rechargeable (secondary) and usually based on lithium chemicals.
Batteries in cars are generally used to power electronic devices and lighting in cars, whereas BKEs are specially produced to power the vehicle to travel for certain distances and periods.
To fulfil the design objectives, it must have a high kilowatt-hour (kWh) energy. In short, batteries for EVs are detailed through a relatively high power-to-vehicle weight ratio; smaller and lighter batteries are practical as they reduce the vehicle's weight and will improve driving performance.
The most typical type of battery in modern EVs is lithium-ion batteries (LIB) due to their high energy density relative to their weight. Other rechargeable batteries used in EVs include nickel-metal hydroxide (Ni-MH).
While lead-acid and nickel-cadmium batteries are not favoured due to the toxic elements, primary (non-chargeable) batteries such as zinc-air batteries are also used for remote area assignment conditions.
EV have a battery capacity of between 6.0kWh (2012 Renault Twizy) and 100kWh (Tesla Model S 2021).
In the beginning of the 1990s, driven by the development of mobile electronics such as laptops, cell phones, and power tools, prompted advances in battery technology.
It is estimated that cumulative output in the range of 0.33 million metric tonnes to 4 million metric tonnes of LIB could be generated between 2015 and 2040.
Before the widespread usage of EVs, where global consumption is around 2.2 per cent, an important element is ecosystem disposal and recycling.
Every beginning will have an end, so will the lithium battery cell. It will be discarded for disposal. Although the start of its construction involved a green technology process, at the end of its life, it returns to toxic materials, heavy metals and some other chemicals that will pollute the environment and the health of life if not handled prudently.
While not all battery components can be recycled, at least some effort has been considered. LIB waste contains a source of precious metals and is capable of recycling. LIB components consist of cathode, anode, electrolyte, and separator polymer components.
The focus of recycling is on cathode materials compared with other elements due to the presence of transition metal oxide materials that could be manipulated for different applications.
Precious metals that are the main recycling topics are lithium, cobalt, manganese and nickel. Meanwhile, carbon-based anode materials can be effortlessly recycled because of their inert nature and do not easily react chemically during use in LIB.
For example, graphene is the result of anode recycling and is deemed the most flourishing material ever made by materials engineering researchers.
Recycling for LIB usually involves physical and chemical processes. The physical process usually includes pre-treatment and recovery of the electrode material.
These processes typically possess cell dissolution, crushing, screening, magnetic separation, washing, heating treatment, etc.
Chemical methods apply pyrometallurgical and hydrometallurgical operations, usually implicating leaching, separation, extraction and precipitation of electrochemical materials.
Farah NST Online (call), [3/4/2022 8:26 AM]
The development of battery recycling is still in its early stages; the research and industrial levels are still immature.
Among the issues that hinder the production and use of batteries for electric vehicles, the assessment of cost, safety and pollution are still at a level that does not significantly impact consumers.
The challenge will be more complicated to recycle millions of LIB battery cells by stepping up their usefulness in the next few decades.
On the other hand, the collaboration of battery manufacturers to facilitate the design of cells for recycling purposes is crucial. Hence, it certainly requires clear policies and laws to fulfil this noble aspiration.
Dr Nur Azam is Assistant Professor at the Department of Mechanical & Aerospace Engineering, International Islamic University Malaysia (IIUM) and Dr Ahmad is Associate Professor, School of Materials & Mineral Resources Engineering, Universiti Sains Malaysia (USM)