Industry players have proposed various ideas in battery technology to extend the travel range of an electric vehicle. Among them, lithium-metal batteries, also called solid-state batteries, have gained popularity for their potential to overcome EVs’ limited travel range.
Most producers presently use lithium-ion batteries to power their EVs. However, experts say lithium-metal batteries may outperform their lithium-ion counterparts in the future. The two battery types differ in electrolyte composition. Lithium-metal batteries use a solid electrolyte, while the other uses a liquid version.
The electrolyte difference may lead to improvements in energy density, a key factor in determining the range of an EV. Energy density influences how much energy a battery can store, given its volume and weight. Recent reports suggest that lithium batteries may have energy density up to two or three times that of lithium-ion batteries. It translates into a longer travel range for EV drivers.
Extending the travel range of EVs is a primary concern for the sector’s stakeholders. About 58 percent of drivers reported not buying EVs due to range anxiety — the fear of getting stranded if the EV’s battery runs out of power.
This issue does not only limit the development of the EV sector. The global community is highly mobile nowadays. Unfortunately, the transportation sector contributes up to a fifth to the global greenhouse gas emissions. Per the Paris Agreement, EU countries are committed to cutting emissions by 40 percent by the decade’s end. Therefore, authorities have been pushing for a transition toward electric transport.
A new study suggests that there has been a shift in mindsets among drivers, with many becoming more confident about the travel range of their EVs. Advancements in the EV sector, including the development of reliable batteries and charging infrastructure, will encourage more people to use EVs.
Analysts point out the potential of a shorter charging time with lithium-metal batteries. Lithium-ion batteries charge for 30 minutes to several hours, depending on the EV type and charging infrastructure. Meanwhile, there are possible advancements that allow lithium-metal batteries to be charged in several minutes. It makes the time needed to recharge an EV unit comparable to refueling a gas-powered vehicle.
Innovations to lithium-metal batteries may also extend their lifespan. The solid electrolyte is less vulnerable to degradation than the liquid electrolyte. This development will benefit owners because battery replacement is one of the priciest expenses in EV maintenance.
Challenges to Lithium-Metal Battery Adoption
Despite their potential benefits, lithium-metal batteries must overcome several hurdles for widespread adoption in the global EV sector. A primary concern among users is dendrite formation. Dendrites are branch-like structures that can appear on the metal electrode surface of the battery.
These structures can lead to a short circuit within the battery, which can be a potential safety hazard. Dendrites will also reduce the battery life. Experts suggest different strategies to manage dendrite formation on these batteries, such as applying protective coatings on the metal electrode. Some are also developing a new solid electrolyte that prevents dendrites.
Interfacial resistance is another issue in the use of lithium-metal batteries in EVs. Because electrodes and solid electrolytes are composed of brittle ceramics, they cannot form sufficient contact.
Tokyo Metropolitan University has suggested using aerosol deposition in lithium-metal battery development. This process involves accelerating tiny pieces of cathode material toward a layer of electrolyte material. The collision will result in a dense layer with better interfacial resistance.
Currently, battery makers must disassemble a battery unit to understand its degradation process. Researchers have proposed electrochemical impedance spectroscopy to deal with this problem. This method allows battery manufacturers to develop new solid-state batteries more efficiently.
Another issue is the sustainability of the battery production process. Many people have raised concerns about the carbon footprint of mining raw materials and manufacturing EV batteries. Several producers, including Sweden’s Northvolt, have implemented circular manufacturing methods to reduce emissions.
Battery recycling is another solution for the potential sustainability issues. The process involves extracting raw materials from used batteries. The recycling facility will send these useful materials to manufacturers. They can use them to produce new batteries or other products. In 2021, the Swedish Energy Agency provided a fund to develop a large-scale battery recycling facility. The new facility concluded its construction in 2023.
Researchers Propose Alternative Materials
Besides lithium, researchers have also developed alternative materials for EV batteries. Several companies are looking into the potential of installing sodium-ion batteries in EVs. A sodium-ion battery has similar components as a lithium battery — anode, cathode, electrolyte, and separator. The production process is also identical.
Users can detach sodium-ion batteries from the car, which improves safety. It also makes charging more convenient in busy areas with many EVs. Furthermore, the materials needed to produce sodium-ion batteries are inexpensive. The main downside is the limited travel range of sodium-ion batteries when used in EVs.
Finnish firm Stora Enso is also developing a wood-based battery. The raw material used in this battery is lignin, a polymer material that people can find in trees. The polymer makes up approximately 30 percent of the tree. Lignin contains carbon, which is a vital part of the anode. Battery manufacturers usually produce anode with synthetic graphite.
According to Stora Enso, producers can get lignin from waste pulp. The pul is available in a forest-product manufacturing facility. It reduces the carbon footprint created by battery production. New studies reveal that using lignin as an anode material can reduce the time needed to charge a battery.
Importance of Charging Infrastructure
Despite new advancements in the EV battery sector, experts still stress the importance of developing a solid charging infrastructure. Easy access to charging stations will make drivers feel more comfortable traveling with their EVs.
Several countries have rolled out public programs to build new charging facilities. The Swedish Transport Association, for instance, offers a grant that covers the costs of building public fast-charging stations. The Swedish government also offers tax deductions to EV owners who have private charging infrastructure at home.
Experts have also urged the private sector to help with charging infrastructure. They say it will be difficult for authorities to keep up with the growing demand for charging stations by themselves. Sweden had less than 800 public charging facilities nationwide by the end of 2022. Meanwhile, there were 95,000 newly registered EVs.) in the same period.
Nimbnet is a private operator that aims to support the growth of charging infrastructure in Sweden. It serves private passenger cars and heavy-duty vehicles. The operator’s facilities accommodate fast charging to reduce wait time for drivers. Nimbnet also uses sustainable power sources to operate its charging stations.