Emerging battery technology is undergoing continuous research, with advancements focused on enhancing performance, increasing energy capacity, and reducing charging times. Among these developments, solid-state batteries are viewed by many as a significant milestone with the potential to shape the future of electric mobility.
Solid-state batteries differ from lithium-ion technology by using a solid electrolyte rather than the liquid electrolytes typically found in lithium-ion cells. To appreciate this difference, it helps to understand lithium-ion batteries, which feature two electrodes—each with structures that can hold lithium ions within their crystal lattice. A lithium-ion cell consists of a cathode, an anode, a separator, and an electrolyte. The cathode, or positive pole, is composed of materials like LFP or NMC, while the anode (the negative pole) is typically made from graphite. The separator, a thin polymer layer, acts as a physical barrier between the anode and cathode. The electrolyte—a lithium-salt-infused organic liquid—fills the cell’s volume, soaking the electrodes and allowing ion movement from cathode to anode.
Solid-state batteries, however, are structurally distinct because all components are solid. Instead of a liquid electrolyte, a ceramic or solid polymer separator is used, which also functions as the electrolyte. This design change allows solid-state batteries to use lithium metal as the anode material. During charging, lithium ions travel through the solid separator, forming a solid layer of lithium in the anode region, reducing its size compared to the graphite anode in traditional lithium-ion batteries.
While solid-state technology remains in development, early assessments highlight significant benefits. For one, these batteries promise increased energy density, longer lifespan, and improved safety, all in a smaller and lighter package. However, lithium-ion batteries are still the market leader, widely produced and available in various chemistries for diverse applications.
Safety is a primary advantage of solid-state batteries. Unlike the flammable liquid electrolyte in lithium-ion batteries, the solid-state design employs a thicker, more heat-resistant separator, often made from ceramic materials. This separator strengthens the cell’s safety by reducing short-circuit risks, even when cells degrade or are improperly used. Solid-state cells are also more resistant to dendrites—sharp, uneven lithium deposits that can pierce separators, causing short circuits. The thicker solid separator in solid-state batteries prevents dendrite formation, enhancing durability.
In addition to improved safety, solid-state batteries boast higher energy density, largely due to the use of pure lithium metal as the anode instead of graphite. Without the bulky graphite structure, solid-state batteries are expected to achieve energy densities two to 2.5 times greater than lithium-ion cells, according to current studies. The resulting increase in energy density means these batteries could be smaller and lighter—benefits that electric vehicles would appreciate, as they translate to longer ranges and reduced vehicle weight. However, these figures will only be confirmed once solid-state batteries enter the market.
Another advantage is the potential for ultra-fast charging. Early studies indicate that solid-state batteries may charge up to six times faster than current technologies, although this performance varies depending on technological advancements. Some prototypes already show rapid charging capabilities, although this can affect other performance factors. Solid electrolytes also benefit from higher thermal stability, improving performance at elevated temperatures, especially during fast charging, when heat tends to build up.
Despite some remaining challenges, the arrival of solid-state batteries in the market seems inevitable, likely transforming sectors where energy density has traditionally been a limiting factor. Their potential for high energy density and rapid charging makes them especially promising for the automotive industry and other areas where space is at a premium for energy storage. Heavy industrial machinery and electric vehicle manufacturers are already showing interest in this technology, particularly for vehicles requiring substantial energy capacity and range. Solid-state batteries could enable broader electrification within these sectors.
If solid-state batteries continue to develop on all fronts, including cost and scalability, they may become a viable option for a wide range of industries, signalling a promising future for industrial electrification.
Ilika plc (LON:IKA) is a pioneer in solid state battery technology enabling solutions for applications in Industrial IoT, MedTech, Electric Vehicles and Consumer Electronics.
