Depending on the technology being talked about, there are already solid-state batteries being commercialized and they could enable a US$8 billion dollar business opportunity in 2033, according to IDTechEx.
What Are Next After Lithium-ion Batteries
Since their invention in the 1990s, lithium-ion batteries have become increasingly popular due to their relatively light weight, compact size, long life span and high energy density.
Fundamentally, a Li-ion cell typically consists of a graphite anode and a layered oxide cathode coated onto current collectors, separated by an organic liquid electrolyte-soaked separator. Packaged in pouch, prismatic or cylindrical formats, they form the basis of Li-ion battery packs. Their comparatively high performance, low cost and wide availability make Li-ion batteries pre-eminent energy storage technology for many applications, from electronic devices to electric vehicles (EVs), to large stationary energy storage systems.
As such, for most applications, Li-ion batteries, in one form or another, are unlikely to be superseded within the next ten years. Nevertheless, due to their performance limitations, and environmental and supply chain considerations, developments and innovations continue to be made for the next-generation battery technologies.
Transition of Effort Focuses
Numerous press releases have been seen on the progress of solid-state batteries and electric vehicle prototypes equipped with solid-state batteries. It seems that the focus on solid-state batteries will mainly be battery cells. However, this will only be part of the future focuses. IDTechEx have seen that the development focuses have experienced a transition from material development & cell demonstration to cell validation and system design. Examples include cell to pack (CTP) design and thermal management systems.
CTP is not a new concept, and it can be found in designs based on lithium-ion batteries, such as BYD’s blade battery and CATL’s CTP designs. The CTP concept will become more important due to the better safety of solid-state battery cells. Battery safety means a more flexible pack design and fewer electronic components used in the battery module/packs.
For instance, the bipolar design enables closer packing and higher energy density. It is possible that initial generations of solid-state batteries may not equip with high-voltage, high-capacity cathode, and lithium metal anode, thus leading to energy densities less than commercial lithium-ion batteries. The initial costs of solid-state battery cells are also expected to be higher than lithium-ion counterparts. However, with higher energy density at pack level with flexible design and fewer materials/components used, it is possible that solid-state battery packs can be comparable to or even better than lithium-ion batteries.
Regarding thermal management system, it is still a necessary system for solid-state batteries. Solid-state batteries may work at a different safe operating area; therefore, the ideal temperature required for solid-state batteries may differ from lithium-ion batteries. Together with the innovative cell design, the thermal management systems mechanical protection can be combined for solid-state batteries system design.
In addition, more and more efforts are being spent on things that are also important for commercialization, such as supply chain building and manufacturing improvement.
Hybrid Now, All Solid-State in the Future
The polymer-based solid-state battery has already been commercialized and used in vehicles, such as the case of Daimler’s eCitaro. Other technologies are continuously testing their samples for the OEMs.
However, most of the commercialized solid-state batteries, and those due to be commercialized soon, are hybrid batteries, meaning they may contain a small amount of liquid or gel. Strictly speaking, they are not all solid-state batteries. While from the end user’s point of view, they do not care what technology to deploy; as long as batteries provide the required features, they are acceptable. Even hybrid solid-state batteries can still provide improved performance, and they could act as a good transition route.
As technologies are becoming more and more mature, the move to all solid-state batteries can be seamless.