The Lithium-ion problem
The Lithium-Ion battery powers nearly every new electrical gadget that is produced in this day and age; it has impressive capabilities to power tech. This wonder battery powers everything from mobile phones to laptops and a host of domestically used items. As well as these uses in the industrial world, the Ion battery has many uses, from everyday objects to the more exotic guidance systems for helicopters and submarines. It is considered such an important invention that the Nobel prize for chemistry was awarded to the three scientists who developed it. The big issue with the Ion battery is though it has an unhealthy dependence on cobalt.
The mineral cobalt is a scarce, poisonous and glossy metal and it is used in the cathode of nearly all Ion batteries that are in production at this time. The issue surrounding the ongoing use of cobalt are numerous. For one, mining costs are exorbitant, it is difficult to extract, causes significant environmental problems (linked to unethical mining practices), the market price fluctuates wildly, and the supply chain of this precious mineral is very flaky. With these factors in mind, it is easy to see why producers are looking for alternatives. The problem is the properties cobalt brings to the table; it gives the battery maximum capacity to store energy and also stabilises their performance. Some alternatives; without the cobalt element, have been tried, but they all fail to match cobalt’s properties in battery performance till now.
A replacement for that troublesome Cobalt
After much research, centred on the work done at the University of Texas, a paper was published which looked at the properties of a cobalt-free battery cathode. The three researchers involved found that by replacing cobalt with nickel in the cathode, on a small scale lithium cell battery, the results were impressive. With this new cathode source, they found the batteries were capable of working at greater voltages for similar charge times. There was a small decrease in energy density. Still, in repeated tests the nickel cathode was found to work as well as its alternatives, these tests were run to match the expected lifespan of a cobalt cathode, and the results were impressive.
In the research paper, the lead author Arumugam Manthiram (Director of Texas Materials Institute) laid out a case for moving away from the use of cobalt in Lithium-ion batteries. The study showed that far from having an adverse effect on the battery’s performance, as many critics have said would be the case, the new cell without cobalt is just as viable.
A lithium-ion cathode is made up of about twenty per cent pure cobalt. The cobalt part of the cathode comes in two different types, either Nickel Manganese Cobalt Oxide (NMC) or Nickel Cobalt Aluminum Oxide (NCA). The main task of the cobalt is to stop the cathode eroding, which can lead to dangerous battery fires, and it also helps to stabilise the battery. The base cobalt product is tough to extract, and even though the use of cobalt boosts battery charge rates, it is also costly. As well as the expense of the cobalt, its mining and extraction have led to widespread criticism of the industry from human rights organisations. The Democratic Republic of Congo is where over 60 per cent of the world’s cobalt supply is produced, usually during nickel and copper production as a by-product. Unfortunately forced child labour and appalling conditions are experienced in the many smaller independent mines that have sprung up around the country. In these mines often in sparsely populated parts of the Congo, it is hard for officials to make sure right working conditions are observed.
The first hurdle
The team at Texas University have come up with a way to overcome this reliance on cobalt. They achieve this by substituting nickel for the cobalt, with nearly ninety per cent of the weight of the cathode being nickel-based. By combining the makeup of the two main cobalt batteries (minus the cobalt), they have created a Nickel Manganese Aluminum Oxide (NMA) cathode. Unlike many previous attempts by fellow scientists, the new battery cell does not suffer from shortened lifespan or low density of energy capacity.
The work by the Texas Materials Institute has been scrutinised by outside laboratories such as the Battery Laboratory at the University of Michigan. Greg Less, the director of the lab, said that the teams work on the cathode “showed great promise” and scientists agree that electrodes that can perform with the same capacity as cobalt cathodes would be a welcome breakthrough. In previous attempts to develop a cobalt-free battery, the manganese component has tended to dissolve as the temperatures were increased. Still, this new NMA cathode seems to have overcome this hurdle although more testing will be required.
The first stage of the making of the cathode involved trying out the mixture of ingredients on a very small scale, using very specialist techniques. They used a reactor to mix an ionised solution with the elements (nickel, manganese and aluminium) so that the metal ions would become bonded. You are then left with the metal hydroxides in a fine powder. This is then added to lithium hydroxide, and this produces the basis of the material used for the cathode. Finally, the ingredients are baked together at extremely high temperatures.
By using their knowledge of chemistry and controlling the process, the team at Texas were able to achieve mixing on an atomic scale. The end product cathode had to be structurally sound, and this was achieved by making sure that the temperature and the pumping rates at which the materials were mixed were precisely controlled.
Using an experimental lithium-ion battery cell with a standard graphite anode, the team added their mixture in the form of the newly created cathode. After observing the testing, it was observed that the results were comparable to the performance of cobalt-based lithium-ion based cells that are commercially available. This involved numerous charging cycles and mixing up the rates at which the cathode was charged. One advantage cobalt cathodes still enjoy is having a higher density of energy (leading to fewer ions being stored). Still, the team at Austin are convinced that by further testing they can achieve comparable results to this small difference.
And now for largescale production
The next phase of this new product is to move from laboratory-based production to large scale industrial manufacture. In order to further this goal, a company Texpower has been established to market the possibilities of this new nickel-based cathode. By using techniques already utilised in the manufacture of battery cells across the industry the production will be easily achieved, and the product will be of benefit to consumers in the form of the many gadgets used, as well as to electricity companies looking to store excess power capacity.
The team are hopeful that this new cathode, free of cobalt, will be available to purchase very shortly. In this respect, they will have much competition it is expected. Big producers are working nonstop to produce lithium-ion cells without relying on cobalt such as the electric car manufacturer Tesla and announcements about this are soon expected. The Oak Ridge National Laboratory, part of the Dept. of energy is producing under licence a cathode for a new company called Sparkz, and large battery manufacturers such as Panasonic have joined the race to develop batteries less reliant on or free of cobalt.
Still some fight left in the Cobalt industry
The cobalt industry is, of course, not giving up the fight at this stage, millions upon millions of pounds have been spent developing the technologies which give us the existing lithium-ion batteries we use almost daily. They point to the reliable performance and the stableness of the cobalt-based cathode, which has been proven over many years. It will be a massive enterprise to create the conditions for the mass production of these new cobalt-free cathodes, and in the meantime, there will still obviously be a great demand for the older technology. It remains to be seen how far ahead in the future if at all this new technology gains the ascendency.
The demand for lithium-ion based is going to increase multiple times over the next few years, with the World Bank predicting a whopping five hundred per cent increase in demand. The amount of cobalt that can be mined in the Democratic Republic of Congo is, of course, finite and several new ventures are underway in many different countries looking for cobalt deposits. Some involve deep-sea mining as many cobalt depositories are found on the ocean floor and this, in turn, is a profoundly divisive field of exploration due to the environmental factors at play. Regardless of whether the cobalt industry can overcome these issues, and that is highly doubtful, what is clear is the advantages of cobalt-free batteries are manifest. From an environmental prospect and from a financial position, it is clear that lithium-ion batteries without cobalt are a winning combination.