Battery technology remains an obstacle for electric vehicles (EVs), yet solutions are on their way. By improving charging times and developing innovative battery technologies, EVs should soon overcome any of their current hurdles.
Nickel, cobalt and rare earths are key ingredients in lithium batteries; sodium-ion batteries do not use these materials and could significantly lower costs.
Lithium-ion
Lithium-ion batteries use lithium and oxygen ions to store electrical energy, with benefits including high power density, cycle durability (battery life) and ease of charging; making them popular choice among electric vehicles, cordless tools and mobile phones alike. Lithium-ion batteries typically come in metal cases equipped with vent holes designed to release excess pressure when required.
Nickel-cadmium cells operate using similar principles as lithium ion cells but with higher cell voltage of 3.6 volts and are more flexible in design – one cell can connect in series with multiple other cells instead of three 1.2-volt cells in series as with nickel cadmium batteries.
Lithium-ion batteries require an anode made from carbon or another material capable of intercalating lithium ions and conducting electricity for them to work correctly. Graphite is the most popular anode material; other options have higher capacities or voltages. Once assembled, these components must then be immersed in an electrolyte medium that separates cathode from anode using an organic solvent like ether that acts as an electric shield while still permitting lithium ions through. The separator must prevent electrons from passing to either end while still permitting lithium ions through.
Over time, a battery may develop a layer of solid electrolyte interphase, or SEI, on its anode, which reduces charge availability and ultimately compromises its performance.
Lithium-ion batteries are an ideal choice for renewable energy systems that utilize solar or wind power and store it for peak demand periods, like during an electric storm. Furthermore, traditional sources like coal or oil can be stored. Linde’s Li-ION technology meets all sustainability criteria by being 100% emission free while using less energy overall for equal output.
Sodium-ion
Although lithium-ion batteries continue to dominate the EV market, sodium-ion technologies are beginning to make headway. These safer batteries operate across a wider temperature range without needing rare materials like cobalt. Furthermore, sodium-ion cells have proven more durable and can withstand several thousand charge/discharge cycles than lithium-ion cells; however, neither have yet reached their energy density and performance capabilities of their counterparts.
Li-ion batteries use lithium as their charge carrier, while sodium-ion batteries (SIBs) utilize aluminium as both anode and cathodes, leading to much lower costs than their lithium counterparts that utilize copper current collectors in both anodes and cathodes. Furthermore, sodium is significantly cheaper to extract and purify, giving companies access to lower production costs for production SIBs while competing with lithium-ion EV batteries in mass market EV industry production.
SIBs must improve their battery performance and stability to compete with lithium-ion batteries. For instance, they must operate at low temperatures while withstanding high cycling. Furthermore, they should hold onto charges for long periods of time. In order to do this, scientists have developed an X-ray technique capable of monitoring internal structures of SIB batteries in real time.
Few companies are currently developing sodium-ion batteries for use in electric vehicle (EV) applications, undergoing testing in various vehicles and charging stations while also trying to cut costs through alternative raw material sources such as Faradion Energy’s announcement that they intend to open a plant by 2023 to produce 0.6GWh annually – yet without providing more details regarding its technology.
Solid-state
Solid-state batteries have become the darling of the EV world due to their promise of longer battery life, increased range and faster charging times. Their concept is straightforward: replacing current EV batteries’ solid electrolyte with another material allows ions to freely flow between electrodes while decreasing risk of overheating and fire.
Ford, Toyota, BMW and Volkswagen have invested heavily in developing solid-state batteries for electric vehicles (EVs). Their hope is to use this technology mass produce EVs more appealingly and reduce range anxiety for drivers considering making the switch.
Solid-state batteries may require greater technical expertise for production, but can charge faster and deliver 2-8 times greater energy density than lithium-ion batteries. Furthermore, solid-state batteries could potentially be safer due to less toxic materials used. They won’t become available for consumer purchase until 2025; but may eventually replace lithium-ion batteries in electric vehicles (EVs).
Solid-state batteries can be divided into three main categories depending on their electrolyte type: oxide, sulfide and polymer systems are each offering their own set of advantages and disadvantages. Sulfide offers higher ionic conductivity at lower processing temperature while being thermochemically stable as well as producing hydrogen sulfide byproduct during operation, yet is yet unprofitable due to high costs and byproduct generation; Polymer systems on the other hand are easier to manufacture while reaching energy densities comparable to their sulfide counterparts.
Small cells
Electric vehicles (EVs) can help drivers reduce their carbon footprint, yet many drivers worry about range anxiety and lengthy charging times. With new battery technologies offering potential solutions to address these concerns and hasten adoption.
Current electric vehicle (EV) designs use lithium-ion batteries, which offer the highest energy density and longest cycle life; however, these cells can be costly and sensitive to temperature change. To address these problems, researchers are developing new chemical formulae that make battery cells smaller and more durable.
Small cells offer an exciting alternative to lithium batteries. Constructed of various materials and featuring higher capacities than large format batteries, small cells offer several distinct advantages over lithium. Furthermore, their recycling materials reduce degradation over time while their production costs are cheaper – perfect for existing battery packs!
Lithium-ion batteries come in two varieties, prismatic and pouch. Prismatic cells are rectangular in shape, while pouch batteries feature flexible metal casing that expands with extreme temperatures, permitting for expansion. Many carmakers specify prismatic or pouch batteries directly with cell suppliers.
Battery manufacturing produces significant emissions, with raw material pre-processing and cell manufacture accounting for over 50% of emissions. To reduce emissions further, production levels can be decreased or alternative materials used; additionally, end-of-life management processes may help lower emissions by decreasing energy usage and encouraging recycling efforts.
Rivian and Lucid are among a handful of companies producing small cylindrical cells with standard dimensions that are wired together into battery packs. This approach uses fewer cells than large-format cells, creating more room within each pack; however, small cells are more prone to sudden capacity loss or shorting and could ultimately fail more frequently than their large-format counterparts.
Modular
Modular battery design is key to lowering the costs associated with electric vehicles, while simultaneously giving engineers more creative freedom when designing them. Reducing battery pack sizes may allow designers to more easily create stylish modern cars – especially important in an EV where power sources are more visible than in an internal combustion engine car (ICE).
Batteries come in all shapes and sizes, but modular battery designs can help manufacturers cut costs by using smaller modules. Furthermore, modular batteries can easily be interchanged for various applications or power requirements – as well as being installed into various vehicles.
Researchers begin the development process for modular batteries by designing its cell chemistry. After creating a prototype suitable for an electric vehicle, this prototype must pass tests that ensure it meets performance specifications before being integrated into a complete battery system and tested again for safety.
Electric vehicles (EVs) are one of the fastest-growing market segments within automotive. They provide both environmental and economic advantages, as well as reduced maintenance costs. Furthermore, EVs are safer than their gasoline-powered counterparts due to no emissions of harmful substances and leakage of flammable liquid electrolyte. Battery technology continues to develop. For instance, Group14 Technologies claims their silicon-carbon anode material increases gravimetric energy density by 25%; solid state battery research could eliminate fire risks associated with lithium-ion systems.
Over the coming years, new battery technology will likely bring down EV prices even further due to improved chemistry, efficient design and flexible module/pack structures.