In the recently published issue of Nature, an article titled "Tenyearslefttoredesignlithium-ionbatteries" pointed out that the evolution of lithium-ion battery performance and price is slowing. If we do not increase the research on electrode materials based on abundant iron, copper and other materials, the large-scale development of electric vehicles will be limited.
Electric cars need powerful, lightweight, and affordable batteries. The best choice is commercial lithium-ion batteries – they are relatively compact and stable. But they are still too bulky and expensive to be widely used.
For twenty years, the performance of rechargeable lithium-ion batteries has steadily increased. The capacity of the battery pack has more than tripled the energy stored, from 200 watt-hours per liter (Wh-1) to 700 watt-hours (Wh-1). The cost has dropped by 30 times to around $150 per kWh. But this is still above the US$100 per kWh affordability target. For electric vehicles (50-100 kWh) The battery is strong enough, but it still weighs about 600 kilograms and takes up 500 liters of space.
As traditional technologies approach the basic limits, the pace of technological advancement is slowing down. The amount of charge that can be stored in the gaps in the crystal structure of the electrode material is close to the theoretical maximum. The expected market growth does not significantly reduce the price – the market is already large .
Researchers have warned that cobalt, nickel and other rare metal substitutes must be found as soon as possible to meet the growing demand for electric vehicle batteries, as their scarcity is pushing up prices: in the past two years, cobalt, nickel and other rare The price of metal has quadrupled from $22 per kilogram to $81 per kilogram. Scientists and engineers are urged to develop cheap, common metals such as iron and copper, as manufacturers cut corners and violate environmental and safety regulations. Potential alternatives.
The researchers say that lithium-ion batteries work by moving lithium ions between the two electrodes. The ion discharge current from the anode to the cathode provides power to the car. When the battery is charged, lithium ions will reflow.
In today's commercial batteries for electric vehicles, lithium ions are held in tiny voids in the crystals that make up the electrodes (these crystals are called intercalated electrodes). The anode is usually made of graphite and the cathode is made of metal oxide. Materials used in electrodes, especially rare metals such as cobalt and nickel, are both rare and expensive.
In our opinion, the most promising alternative is to use a conversion material in the electrode. Copper, iron, fluoride and silicon react with lithium ions. The transition metal in the conversion cathode can hold 6 times more lithium atoms than the standard cathode. This material expands more and can hold more lithium atoms.
If there is no change, demand will exceed production in 20 years. We expect the price of cobalt to rise by 2030, and the price of nickel will rise in 2037 or earlier.
Automakers and the government expect to produce 10 to 20 million electric vehicles a year by 2025. If each car battery requires 10 kg of cobalt, by 2025, electric cars need 100,000-200,000 tons of cobalt per year — - This is the majority of the world's current production. Similarly, 400,000-800,000 tons of nickel is needed each year, accounting for 20-40% of the metals used today. When trucks, buses, planes and boats are switched to battery power, they need more More electricity.
By 2050, the production of 50 million to 80 million electric vehicles per year will require 500,000 to 800,000 tons of cobalt. By 2030, this will far exceed the current mining capacity. Similarly, by 2050, the demand for nickel will be Increase 2-3 times. By the mid-1930s, the shortage of nickel will be obvious.
Recycling can not replenish materials. Lithium-ion batteries have a service life of 15-20 years, which is three times the life of lead-acid batteries in 5-7 years. Refineries may mine poor quality ores, especially in the case of price increases. But higher processing costs will push up prices. Once supply peaks, we estimate that the price of electric car batteries may rise by more than $1,000. If cathodes are made with less metal, 'cobalt peaks' may be delayed for a few years. However, cathode materials that use less cobalt are under development, degrading faster and requiring more frequent replacement.
