Lithium batteries have become indispensable in daily life, found in mobile phones, computers, wearable devices, and new energy vehicles. However, this has also led to concerns about lithium battery resources, especially with the soaring prices of related raw materials this year, forcing countries to accelerate their plans for the "post-lithium battery" era.
Multiple countries are betting on magnesium batteries. The Nikkei Asian Review website reported on the 20th under the title "When will lithium batteries be surpassed?" that the joint research team "E-Magic," composed of renowned engineering universities in the UK, Denmark, and Israel, as well as research institutions in Germany and Spain, is accelerating the development of breakthrough high-capacity and more environmentally friendly magnesium and zinc batteries with the goal of 2030, with the support of EU funding.
The report states that lithium-ion batteries were first commercialized by Sony in Japan in the 1990s. They can store more energy than previous nickel-metal hydride and lead-acid batteries and are now widely used in new energy vehicles, personal computers, and smartphones. Related research even won the Nobel Prize in Chemistry in 2019. However, the biggest drawback of lithium-ion batteries is their high cost. The report cites the example of using lithium-ion batteries for large-scale storage of renewable energy sources such as solar or wind power, stating that data from Japan's Ministry of Economy, Trade and Industry shows that reducing the cost to 23,000 yen per kilowatt-hour, comparable to hydropower, is "a pipe dream."
Therefore, the main goals of the "post-lithium battery" era are to reduce costs and improve durability. "E-Magic" targets the lower-cost magnesium battery. Magnesium ions can carry two positive charges, while lithium ions can only carry one, so theoretically, magnesium batteries can have a higher energy density than lithium batteries. Currently, magnesium batteries in the laboratory can be repeatedly charged and discharged more than 500 times. Researchers will focus on improving the electrolyte and developing new electrode materials. Meanwhile, Toyota's North American Research Institute and the University of Houston are also developing a new magnesium battery, using organic compounds as the positive electrode material and boron as the electrolyte. Although this magnesium battery can currently only be charged and discharged 200 times, the research team claims that they have "found a direction for developing highly stable, high-performance batteries."
In addition to magnesium batteries, the report mentioned that Assistant Professor Hiroaki Kobayashi and Professor Itsuki Honma of Tohoku University in Japan are also developing new zinc batteries. They use aqueous solutions instead of organic solvents as electrolytes, which reduces the risk of fire accidents. Due to their low cost, they are expected to be used for storing renewable energy in the future.
Alternative technologies are not yet mature
Mo Ke, chief analyst at Zhenli Research, told the Global Times on the 21st that, regarding currently developing lithium battery alternatives, in addition to magnesium and zinc batteries mentioned by Japanese media, there is also the relatively more mature sodium battery. In fact, both sodium-ion and lithium-ion batteries originated in the 1970s, and their working principles are highly similar. However, due to the lack of suitable electrode materials, sodium batteries did not achieve a breakthrough until after 2000. The most advanced sodium battery currently available was released by CATL in July of this year, boasting the world's highest energy density (160Wh/kg) and ultra-fast charging capabilities (80% charge in 15 minutes). CATL's next-generation sodium battery is expected to exceed 200Wh/kg in energy density; a basic industrial chain is planned to be established by 2023.
Mo Ke believes that, based on current development, magnesium, zinc, and sodium batteries are still far from being commercially viable on a large scale, and some are even still in the laboratory stage, with numerous performance defects. He stated that the enthusiasm for these lithium battery alternatives stems not from their superior performance, but rather from their greater availability and lower raw material costs.
As mentioned in the Nikkei Asian Review, the distribution of lithium, nickel, and cobalt—the raw materials for lithium batteries—is extremely uneven. Data shows that nearly 80% of lithium production is concentrated in the Four Lakes region of the Americas and six mines in Australia, meaning China needs to import over 80% of its lithium resources. Nickel resources are mostly concentrated in Indonesia, Australia, Brazil, Russia, Cuba, and the Philippines, with these six countries accounting for nearly 78% of global nickel reserves. Approximately 51% of the world's proven cobalt resources are located in the Democratic Republic of Congo. In contrast, the reserves of sodium, magnesium, and zinc are much higher. For example, lithium reserves in the Earth's crust are only 0.0065%, with global reserves of only 86 million tons, while sodium reserves in the Earth's crust are only 2.74%, with sodium salt reserves in China's Qaidam Basin alone reaching 321.6 billion tons.
On the other hand, magnesium and zinc batteries still face considerable technological and material hurdles. Suitable electrode materials have not yet been found, let alone large-scale applications. Mo Ke predicts that considering the process of a new technology going from laboratory research to mass production and large-scale application, these alternative technologies may need to wait two or three decades to mature. He also stated that even relatively mature sodium batteries, due to the relatively large radius and volume of sodium ions, are limited in terms of energy density improvement, and may be more suitable for energy storage batteries, two-wheeled electric vehicles, and other fields with lower energy density requirements. CATL revealed that it has developed a system that combines sodium and lithium batteries, allowing them to "complement each other's strengths."
There is still room for improvement in lithium batteries.
If lithium batteries are difficult to replace in the short term, what about their future? Mo Ke believes that the soaring prices of lithium battery-related raw materials this year have been artificially inflated. In terms of lithium resource reserves, although they are far less than those of sodium, magnesium, and zinc, they are definitely sufficient for the next 30 to 50 years.
Meanwhile, the potential of lithium batteries has not yet been fully realized. Mo Ke stated that the theoretical energy density of lithium batteries can reach up to 700Wh/kg. Currently, high-nickel 811 batteries (where the positive electrode material contains 80% nickel, 10% cobalt, and 10% manganese) can achieve an energy density of 260-270Wh/kg. In 2021, leading Japanese and South Korean battery companies launched ultra-high-nickel battery products with a nickel content exceeding 90%. Combined with the use of silicon-carbon materials for the negative electrode, this is expected to increase the energy density to 400Wh/kg, equivalent to a 50% increase in the energy storage capacity of lithium batteries. Furthermore, many countries are researching replacing the liquid electrolyte in lithium batteries with a solid electrolyte, which can simultaneously improve both energy density and safety.
