6 Battery Technologies to Watch
New battery chemistries and configurations and innovative manufacturing techniques will help move the energy storage field forward.
Storing electricity in batteries has never been more important. From electric vehicles (EVs) to grid storage, batteries are the key to our future. Lithium-ion batteries are the most popular choice, but lithium is expensive and subject to supply constraints. The future could be filled with other battery chemistries, configurations, and manufacturing techniques. Here are six battery technologies we are watching.
Image used courtesy of Peter Fiskerstrand, CC BY-SA 4.0 via Wikimedia Commons
1. Lithium-Sulfur (Li-S) Batteries: Lithium-sulfur batteries are a good replacement for traditional lithium-ion batteries. They offer several advantages, including a higher energy density, lower cost, and lighter weight.
These batteries use a lithium anode and a sulfur cathode, and they have a theoretically five times higher energy density than traditional lithium-ion batteries. This means that a lithium-sulfur battery can store more energy using the same amount of space as a traditional lithium-ion battery. Prototypes of lithium-sulfur batteries have been used in high-altitude unmanned aircraft and other defense projects, but as yet, they have not been commercialized.
2. Sodium-Ion (Na-Ion) Batteries: Sodium-ion batteries are similar to lithium-ion batteries in terms of structure but use sodium instead of lithium, making them less expensive to produce and more widely available, as sodium is a more abundant element. However, sodium-ion batteries have lower energy density than lithium-ion batteries, a major drawback. Their greater weight makes them potentially useful for grid storage batteries rather than in EVs.
Sodium battery manufacturing in a factory. Image used courtesy of Adobe Stock
Nevertheless, they are still a promising technology due to their low cost and the easy availability of sodium from sources like seawater. Several companies are working on commercial versions of sodium-ion batteries, and production cells are expected to arrive in 2023.
3. Flow Batteries: Flow batteries are rechargeable batteries in which energy is stored in an electrolyte solution that is pumped through a fuel cell to generate electricity. These batteries have several advantages over traditional batteries, including a much longer life span and the ability to store large amounts of energy. The storage capacity of a flow battery depends on the volume of the electrolyte solution, making flow batteries a scalable solution for large energy storage systems.
The most common types of flow batteries include vanadium redox batteries (VRB), zinc-bromine batteries (ZNBR), and proton exchange membrane (PEM) batteries. Each of these configurations has been commercialized and deployed for stationary grid storage, and we expect this application to be the primary driving force for flow battery growth and innovation.
4. Solid-State Batteries: Solid-state batteries are rechargeable batteries that use a solid, instead of liquid, electrolyte. Commercial lithium-ion batteries use a liquid electrolyte made from highly flammable organic ethers that can produce an intense fire if ignited. The solid electrolyte in a solid-state battery is made from either a polymer or ceramic material, making these batteries safer than traditional batteries, as there is no risk of leaking or combustion.
Solid-state batteries can be designed to be lighter and thinner than traditional batteries, making them ideal for portable devices, and some very small-sized solid-state cells have already been commercialized.
Many consider solid-state batteries to be the Holy Grail for EVs as if equipped with a thin film of lithium metal for the anode. They can produce 2-3 times the energy density compared to traditional batteries that use a graphite anode.
Solid-state batteries face several challenges before they are ready for widescale adoption in EVs. Fabrication of the cells is difficult, requiring different machinery than current battery manufacturing equipment. Some solid-sate electrolytes (particularly ceramics) operate better at high temperatures. The solid is also prone to cracking, and problems along the electrolyte and electrode interface have been observed. Still, several companies are working on the concept, and it is estimated that they will find their way into large-scale usage within the next 5-8 years.
5. Metal-Air Batteries: Metal-air batteries are rechargeable batteries that use pure metal as the anode and oxygen as the cathode. They have a very high theoretical energy density, making them ideal for large-scale energy storage systems. However, they are still in the early stages of development and have not yet been commercialized. The exception is non-rechargeable zinc-air batteries widely used in hearing aid devices.
Some of the major challenges that must be overcome before metal-air batteries can be used on a large scale include improving the efficiency of the oxygen cathode, developing a reliable and safe air-management system, and reducing the cost of production.
Another challenge is producing batteries that can be charged and discharged several thousand times—at present most configurations allow less than 100 cycles. In addition to zinc, aluminum, magnesium, lithium, sodium, and iron are all being studied for their potential use in metal-air batteries.
6. 6K Energy Cathode Fabrication: More than 85 percent of the materials used in lithium-ion batteries are sourced from China. There is a strong effort underway to create North American sources for battery materials, and a company called 6K Energy has developed a production technology using a microwave plasma system (called UniMelt) that can produce battery cathode materials in a sustainable, environmentally sound way that is scalable at an attractive cost.
UniMelt. Image used courtesy of 6K Energy
The company was named to Cleantech Group's 2023 Global Cleantech 100 list, an annual recognition of the most innovative companies working in the Greentech sector to achieve decarbonization. The UniMelt microwave plasma can create powdered battery materials (nickel-based and iron-phosphate-based cathodes) with 90 percent less water and zero wastewater to create cathode materials sustainably and has the potential to aid in developing domestic sources for lithium-ion batteries.
More Battery Innovations Where That Came From
These six new battery technologies are not the only innovations that are helping to move the electrification of everything forward. Nevertheless, they are among some of the most promising technologies to help revolutionize the world of energy storage.
Lithium-ion batteries have gotten off to a good start, and grid storage and EVs are now becoming much more commonplace. By constantly looking for ways to improve energy storage—including higher energy density, longer life span, improved safety, more environmentally sound and sustainable manufacturing, and lower cost—the future of energy storage looks bright as these new technologies pave the way for a cleaner and more efficient energy system.