With the world we live in becoming ever more electrified, new and innovative storage technologies are now emerging in order to satisfy demand in a more sustainable way.
Whether it’s in your smartphone or electric car, lithium ion batteries have become the most commonly available batteries, in part due to their high energy density and ability to retain their charge with little energy loss.
However, with a rise in demand for electric vehicles and all other kinds of rechargeable electronics, manufacturers are looking for other sources of energy storage. According to BloombergNEF, “Lithium Carbonate Equivalent (LCE) demand is expected to increase to 3 million metric tons by the year 2030 from 1.2 million metric tons in 2024.”
According to a 2024 article on Mining.com, “An expected 115,000 metric tons LCE surplus next year should put the lid on any near-term price spikes. Although due to lag effects of mined material moving through a growing supply chain, the effective inventory build at the margin is much lower.” Though there is currently a surplus, with demand to increase so significantly over the next few years, there is speculation supply may not be able to meet demand.
CATL, a Chinese battery company, thinks they have a viable alternative to the lithium-ion battery: sodium. The Naxtra battery is the first sodium ion battery to reach mass production, with a line of two batteries made for electric vehicles, one for regular passenger vehicles, and one for heavy industrial vehicles. According to CATL, “With sodium’s inherent safety and abundant reserves, it efficiently reduces dependence on lithium resources and strengthens the foundation of new energy technologies, while promoting energy utilization from ‘single resource dependence’ to “energy freedom.’”
Sodium is roughly 1,000 times more abundant than lithium in the earth’s crust and approximately 60,000 times more abundant than lithium overall. Lithium ion and sodium ion batteries both consist of the same primary components: cathodes, anodes, electrolytes, a separator, and current collectors.
A lithium ion battery cell usually consists of a graphite anode, lithium-based cathode, and a dissolved lithium salt electrolyte. However, a sodium ion battery uses a sodium layered oxide or sodium iron phosphate cathode, which are cheap and abundant. Instead of a graphite anode, (of which China controls 90% of the world’s supply) sodium ion anodes consist of hard carbon which can be made from biomass, pitch, or waste materials. The sodium ion battery’s electrolyte also uses sodium salts which are much cheaper and abundant compared to lithium salts.
According to the American Chemical Society’s Publications, “The foremost advantage of sodium ion batteries comes from the natural abundance and lower cost of sodium compared with lithium.” It continues, “The overall cost of extraction and purification of sodium is less than that of lithium. Moreover, sodium-containing metal oxide and polyanion cathode materials can be fabricated from naturally abundant transition metals such as iron, manganese, vanadium, and titanium, without using cobalt, making sodium ion batteries sustainable and affordable in rich and poor countries alike.”
However, right now sodium ion batteries are limited to use in larger less versatile capacities, as current sodium batteries have an energy density lower than lithium ion. Energy density is simply how much energy a battery can store in a given weight or volume, typically measured in watt hours per kilogram or watt hours per liter, (wh/kg and wh/l respectively.) For example, lithium ion nickel manganese cobalt (NMC) batteries used in a variety of performance electric vehicles can exceed 250 wh/kg, while the most advanced sodium ion electric vehicle battery only makes approximately 175 wh/kg.
In an economic climate with China and the United States locked in a trade war, the availability and price of raw materials is extremely important. According to the US Energy Information Administration, “In 2022, Chinese companies accounted for over two-thirds of the world’s cobalt and lithium processing capacity.” This means when it comes to control of lithium ion batteries “As of 2025, China produces approximately 85% of the world’s lithium-ion battery cells by monetary value, making it the dominant global supplier. This includes batteries for electric vehicles (EVs), consumer electronics, and energy storage systems.”
With the emergence of renewable energy such as solar and wind, a new solution to store the energy has also emerged: sand. While not technically a battery in the sense of storing and producing energy via electrochemical reaction, sand batteries could still be the next big thing in clean energy storage.
Sand batteries work by taking energy from renewable sources and storing them as heat. Aimed at replacing fossil fuels for district heating and domestic use, this new source of storage first became used at scale in Finland, after it joined NATO in response to the Invasion of Ukraine in 2022.
As a response to Finland joining NATO, Russia cut off exports of gas and electricity, forcing Finland to rely even more on renewable energy sources and find new ways to store it. According to Araner.com, ”In 2023, renewable energies were already responsible for 42% of the national heating share (the largest share). At the time of the report, biomass, particularly wood fuels, and recovered heat were the main renewable sources.”
Sand batteries, consisting of low-grade sand stored in large insulated tanks use excess thermal energy produced by these renewable sources and store it at around 600 degrees Celsius (or 1112 degrees Fahrenheit) via electrically powered heating element. When heat is needed, a large fan circulates the hot air which is used to heat water in a heat exchanger, which is then sent through pipes for use by the consumer, replacing fossil fuel and electric powered water heaters.
Although other thermal batteries like molten salt and concrete batteries exist, sand is being proposed as a replacement due to its higher potential for heat storage, abundance, and durability. Sand is extremely low maintenance and unlike molten sodium, is not corrosive to the heating element it requires.
Sand batteries can also be used to create electricity, using the heated water to produce steam which could then power a turbine and generate electricity. However according to Polar Night Energy, the creator of multiple industrial scale sand batteries, electricity generation is only about 30% efficient wasting 70% of heat energy, but is working to improve to a 70% efficiency rate.
As the demand for energy storage worldwide continues to grow exponentially, so does the need for diverse ways to store it. With the future of lithium ion and fossil fuels uncertain due to a lack of supply of raw materials, trade restrictions, or a myriad of other factors, the future of energy storage is likely to rely on abundant, cheap, and safe materials.
