Lithium-ion batteries are the dominant energy source for grid reliability, but there is a pressing need for more sustainable and versatile battery technologies. This urgency is heightened as renewable energy sources are added to the energy grid system.
Energy storage systems (ESS) are becoming indispensable for modern energy grids. As renewable energy sources like solar and wind, which are inherently intermittent, are used more often, ESS provide the critical functionality needed to balance supply and demand, enhance grid reliability, and support energy independence. The lithium-ion battery is currently the standard, but it has issues. Among them is the fact it does not support the ethical sourcing of limited natural resources.
As a result, the hunt is on for battery technologies that are more sustainable and versatile. Plus, with companies and governments open to hearing unique solutions, there is space for breakthrough innovation. Suppliers in this field – and especially traditionally overlooked, more diverse, or smaller suppliers -- thus have an excellent opportunity to contribute to the evolution of large-scale energy storage options in support of the grid.
The Current Standard: Lithium-Ion Batteries
Lithium-ion batteries dominate the energy storage landscape thanks to their high energy density, efficiency, and declining costs. They are a crucial element of grid energy storage systems, ensuring the consistent flow of electricity from wind, solar, and other renewable energy sources. Their scalability has made them a preferred choice for both residential and utility-scale applications. Other features that have contributed to their popularity are their higher energy-to-weight ratio, which supports a wide range of applications, 85-95% efficiency in terms of energy loss, and costs driven down by a well-established supply chain and economies of scale.
The most troubling issue is that lithium-ion batteries come from non-renewable and limited natural resources, such as lithium, cobalt, and nickel. While the batteries are used in climate-friendly and green projects, they are not particularly climate-friendly or green themselves.
There are also serious ethical concerns around the production of these batteries that many people may not have on their radar. One is the mining practices that lead to habitat destruction and water depletion. Another is human rights violations, as countries that are major producers of the minerals use child labor and forced labor. Communities near mining sites contend with health problems due to environmental contamination and experience water shortages. Lithium-ion battery manufacturing is energy-intensive, and there are currently inadequate solutions and infrastructure for end-of-life battery disposal and recycling. The fact they contain rare materials complicates the disposal and recycling process.
The current reliance on lithium-ion batteries will change in the future. Developers are actively working on solutions that could revolutionize the large-scale energy storage landscape. These emerging technologies hold the promise of mitigating the sustainability issues associated with lithium-ion batteries, offering a hopeful glimpse into the future of energy storage.
On the Long Road to Developing New Battery Technologies
Some progress has been made in the development of new battery technologies. The industry welcomes innovators and developers with new ideas for unique battery types supporting environmental sustainability and energy needs. One of the promising solutions is the sodium battery. This emerging battery (Na-ion) is more environmentally friendly because it uses inexpensive sodium to replace lithium, and salt is abundant in the ocean. These batteries do not use nickel or cobalt and can incorporate lower-cost materials like aluminum foils. It also requires less water to extract sodium compared to lithium. The sodium-ion batteries are already in use worldwide.1
The major drawback of sodium-ion batteries is their lower energy density compared to lithium-ion batteries. This means they will not last as long as lithium-ion batteries. Scientists are working on this issue and are likely to develop a solution.
Solid-state batteries replace the liquid electrolyte in lithium-ion batteries with a solid one, offering higher energy density and improved safety. The higher energy density means these batteries can store more energy in the same space size as the lithium-ion battery. Safety is improved because the batteries do not contain flammable liquid electrolytes. Solid-state batteries charge faster, last longer, and are lighter. They have a longer lifespan, and it is believed that these batteries could help to add more renewable power to the grid since some newer developments do not require temperature regulation that utilizes energy. The challenges include manufacturing scalability, long-term stability, and cost-effectiveness. These are still significant challenges. However, there is a growing belief among researchers that they can be overcome, and widespread adoption of these batteries is inevitable for electric vehicles and the electric grid.2
A third emerging grid-scale battery is the flow battery. Flow batteries store energy in liquid electrolytes contained in external tanks separated by a membrane, making them ideal for long-duration storage. Electricity from renewable sources like solar and wind power drives a reaction that charges the battery. The battery releases electrons through an external circuit to power the grid. The process reverses to recharge the battery, a process which electricity from renewable energy sources can drive. This cycling process could conceivably work for years.
The large capacity flow battery can store intermittent renewable-sourced energy and balance the grid energy load. The challenges the developers are working on include the lower energy density compared to the lithium-ion. There are other issues to resolve, too, like the faster degradation of electrolytes compared to other batteries.3
Energy Storage Systems are Key to Increasing Renewable Energy Sources
The evolution of energy storage systems is pivotal not just for the future of sustainable energy but also for global energy independence and a resilient energy grid. While lithium-ion batteries remain the industry standard, emerging technologies like solid-state, flow, and sodium-ion batteries promise to address existing limitations. Large-scale energy storage projects are already demonstrating the transformative potential of energy storage systems in enhancing grid stability and enabling renewable energy integration. As these systems continue to mature, they will play an increasingly vital role in supporting these global energy goals.