As time goes on, our modern world becomes increasingly reliant on battery power and storage. By 2030, this new electrified world is projected to consume up to 10 terawatt-hours (TWh) of batteries annually. By 2021, we will be using approximately 0.5 TWh. Due to these projections, concerns have arisen about whether raw materials can meet this demand. Batteries made with lithium-ion (Li-ion) technology have become the dominant technology of the modern era (and will be used in the future), and the supply of nickel and cobalt is extremely limited globally.
Scientists at Berkeley National Laboratory have made progress in creating battery cathodes using new materials that provide similar or even more energy than conventional lithium-ion batteries. The key difference in this new type of battery is that it can be made from abundant and inexpensive materials. Disordered rock salt containing excess lithium (also known as DRX) is a recently synthesized new type of material that can also be used to construct cathodes that do not contain cobalt or nickel.
This reduces reliance on key minerals for the future and minimizes the risk of supply chain issues. With the integration and eventual takeover of DRX materials, it provides a new platform for lithium-ion batteries as the primary sustainable battery type to be used for many years to come.
What is a cathode made of?
A battery consists of two electrodes, one of which is the cathode. The cathode also accounts for more than a third of the battery's manufacturing cost. Currently, the materials used for lithium-ion battery cathodes are nickel, manganese, and cobalt (NMC). The combination of nickel and cobalt with the inert manganese component limits the performance of lithium-ion batteries at this point. The only way to achieve higher performance from these batteries is to use alternative materials, such as the aforementioned DRX material. These offer significant flexibility in composition and allow the use of many abundant materials in their structure. This gives these materials some very powerful properties, one of which is that any kind of metal can be used to fix any problems that may arise.
Why not continue using nickel and cobalt?
Minimizing the use of cobalt in battery production has become a top priority for the U.S. Department of Energy (DOE). Global nickel production would be completely consumed if existing resources were assessed at only 2 TWh, while current cobalt production wouldn't even meet demand. Meeting 2 TWh of production would require approximately 2,000 kilotons of cobalt and nickel, while today's cobalt production is only about 150 kilotons. Increasing cobalt production to that level is not feasible.
Furthermore, more than two-thirds of the world's nickel supply is used in the manufacture of stainless steel. Over 50% of the world's cobalt supply comes from the Democratic Republic of Congo. Australia, Russia, Cuba, and the Philippines are also major cobalt producers.
Conversely, cathodes made from DRX can use almost any metal to replace cobalt and nickel. Titanium and manganese are being explored as alternatives because these metals are more abundant and cheaper than cobalt and nickel. Titanium oxide and manganese oxide both cost less than $1/kg, while nickel costs $18, and cobalt costs as much as $45/kg!
The DRX offers the opportunity to create extremely cheap battery power, at which point lithium-ion batteries will face no competition from any other type of battery on the market. It will also have a ripple effect on other industries, as battery power will become cheaper in the automotive and other sectors.
Making rapid progress in a slow market
In the past, new materials used in battery manufacturing took 15 to 20 years to reach the market, but DRX materials are expected to develop at a much faster pace. Significant progress has been made over the past three years, and now a larger team is needed to bring in experts and their diverse skills to keep this new technology on track for commercialization.
This new, larger team will also help address the few remaining issues facing batteries, including optimizing the electrolyte, the medium that guides the charge from the cathode to the anode and extends cycle life. Cycle life is the number of times a battery can be recharged before it becomes unusable. In recent years, Japan and Europe have also launched numerous new DRX research projects.
To continuously advance new battery technologies, fundamental breakthroughs in materials science are essential. Since DRX is composed of so many variable elements, researchers will have to experiment and learn from mistakes to ensure they use the best possible materials while achieving a balance between abundance, performance, and affordability. Because of DRX's high flexibility, the entire periodic table must be considered when constructing materials. This will determine the battery's charging speed and the materials' stability—both crucial characteristics of high-performance batteries—and will contribute to the development of batteries capable of solving many real-world problems.
