Achieving high-energy-density batteries with innovative chemistry, materials, and engineering will require decades of continuous research efforts.Â
The Future of Advanced Batteries
Today, advanced batteries are a key enabler in the seamless integration of renewable energy systems. By storing excess solar power to be used at other times, they help level out the intermittent nature of renewable energy production and reduce the need for grid-supplied electricity.
Current research is focused on reducing the ecological footprint of batteries by shifting toward more abundant and environmentally friendly materials. This can be achieved by using cheaper, more easily recyclable, and safer electrode materials such as lithium cobalt oxide, sodium-ion, or graphene. New architectures that eliminate the need for lithium and other sensitive materials could also create long-life, MWh-scale stationary batteries to supplement residential, commercial, and industrial energy usage.
Developing emerging electrode materials for battery applications requires multidiscipline and multifield collaboration. Understanding the controlled synthesis, reaction mechanisms, and structure-performance correlations of these materials depends on detailed structural and chemical analysis from millimeter to atomic scale. The availability of standardized and open data sets for these critical materials accelerates knowledge-led progress and drives innovation.
The Minerals
Of the energy transition technologies poised to boom in coming decades, none is expected to put a bigger strain on minerals supplies than batteries. The IEA’s bottom-up assessment of policy commitments suggests the world is on track for a doubling of demand by 2040, led by growth in electric vehicles and energy storage used to balance out wind and solar on the electricity grid (see chart).
Nickel, cobalt, and lithium are critical for battery cathodes, with cobalt presenting the greatest procurement risk given its highly concentrated concentration in conflict zones. Its supply is highly volatile, and the development of low-cobalt or even cobalt-free cathodes could significantly trim overall battery demand. The IEA’s latest assessment of the global mining industry suggests that the current extraction rate for each of these key minerals is set to peak in 2025, after which it will decline. This decline, combined with increased recycling, will help ensure that mineral resources are able to meet demand over the long term.
The Cases
The battery components used to store and release energy in EVs need to be robust and stable across wide temperature ranges. Thermal shock tolerance and abuse-tolerance are also key considerations. One example is porous silicon carbon composites, which have demonstrated high cycling performance with reversible capacities up to 1500 mAh/g. The authors attributed this improved cycling capability to their enhanced surface area and porosity, which allow lithium ions to be quickly transported within the material during charging and discharging.
Another approach to increasing battery capacity is by replacing nickel and cobalt with other metals, such as manganese or iron. These substitutes can be produced experimentally or simulated with the aid of computational tools. However, these materials are generally less energy-dense than those containing nickel and cobalt.
Traceable sourcing is an essential component of EV supply chains, but implementing such a system requires significant effort from manufacturers and affected communities. Legislation like the Conflict Minerals Rule and voluntary efforts such as IRMA could improve traceability, but such initiatives need to be supported by more widespread adoption of responsible business practices among companies and consumers.
The Electrodes
Achieving a high energy density and long battery endurance requires innovative electrode materials. The development of such advanced Battery Materials is an engineering process involving many fields, including physics, chemistry, material science, electronics, mechanical engineering, automation, informatics and others. It demands collaborations across multidiscipline and countries. The successful implementation of emerging battery materials relies on the understanding of their evolution at the atomic, molecular, and material levels while they are working.
Electrode materials used in battery cells are complex composites with different grades and morphologies of conductive carbon, different grades and morphologies of metal oxides or sulfides, and polymeric binder. They contain thousands of interfaces that influence the interfacial properties and the rate at which they grow. Understanding how the varying surface films in these materials affect their performance requires advanced microscopy and spectroscopies.
NREL has teamed up with Ulm University to develop a unique method of using electron backscatter diffraction (EBSD) in conjunction with machine learning (ML) and image segmentation techniques to map the 3D orientation and morphology of individual cathode particles within an electrode. This provides realistic images that can be analyzed and simulated to reveal the dynamic phenomena occurring during charging and discharging.
Innovating practical battery electrodes also requires consideration of the temperature tolerance of these materials. For example, some advanced Li-ion chemistries, such as silicon anodes, show promising performance in thin film form but suffer from severe capacity fade in powder samples. The ability to tolerate a wide range of environmental temperatures may prove critical to their commercialization. Thank visiting foxbpost.com