If lithium and other materials are concentrated in a few territories, alternatives must be found to make storage systems more efficient and improve the supply chain to our advantage.
A critical role in the energy transition in different sectors is played by batteries, whose diffusion is also supported by decreasing costs and the increasing share of electricity generated from renewable sources that increasingly needs storage systems.
In terms of chemistry, today batteries that rely on the use of lithium make up the vast majority of batteries used, which also rely on the use of cobalt, nickel, manganese, and graphite. These are materials that pose a problem when it comes to supply because today the production and processing of these materials are geographically highly concentrated in very few places. In 2019, for example, China was responsible for about 60 percent of global cobalt and rare earth production. Currently, every stage of battery production, from mining the minerals to using chemicals to produce the final battery components, is geographically concentrated in areas outside Europe. By the way, Europe is investing large sums of money in building facilities for cell production, assembly and recycling of batteries to become a key production location. In this direction, the Fraunhofer Research Institute, together with eight other research institutes, has developed the digital twin concept for battery cell production.
The alternatives to lithium
The dependence toward certain materials found only in certain territories drives innovation and paradigm shifts toward optimizing existing technologies and developing new battery solutions. In this area, another key theme is battery recycling and remanufacturing: the opportunities arising from the management of spent batteries are already beginning to incentivize traditional players in the value chain to extend their expertise to adjacent roles.
Toward the cathode focuses the interest of researchers, including those at Fraunhofer ISI, who study lithium-ion batteries along with nickel, manganese and cobalt. Research to replace or diminish these minerals has led to various solutions, including metal-ion, metal-sulfide, air-metal, and redox flow batteries. Sodium-ion batteries have also attracted considerable interest from manufacturers because they do not require critical and expensive minerals such as lithium, but could be produced on the same production lines as lithium batteries, with all the advantages. To date, however, their energy density barely reaches 2/3 of that of lithium batteries, making them unattractive to the automotive industry.
Geographical distribution of batteries’ global supply chain. China dominates in each phase (Source and Credits IEA)
Advantages and obstacles
While on a theoretical level air-metal batteries involve the use of a metal other than lithium, on a practical level they present a number of complications.Another chemical combination that has been paid attention to is lithium-sulfide due to its high energy density, but due to its too short lifespan it is not yet so concretely appealing to the market.
In addition, flow batteries could become an alternative to lithium-ion for stationary storage systems, using vanadium as the primary element, but an obstacle here is economic.
Solid-state batteries are lithium batteries where, however, solid or near-solid electrolytes are used instead of traditional liquid electrolytes, with the goal of increasing the energy density of the cells and their safety. To date, there are limitations in terms of pack-level integration because they are subject to higher battery pressures. However, researchers agree to support the development of these batteries, particularly for applications that require long-range driving, such as electric trucks, especially in markets where the establishment of widespread charging infrastructure or battery replacement might be difficult.
(by Maria Luisa Doldi)
