A Chinese company called Hina made a sodium-ion battery that surprised scientists by matching Tesla's battery quality. The researchers published their study in Cell Reports Physical Science. They used electrical tests and X-rays to test 120 cells. They examined the batteries at temperatures from -20°C to 45°C. 'We were positively surprised by how uniformuniform/ˈjuːnɪfɔːrm/L2一致的，均匀的the same in all parts; not changing or varying the cells are,' said researcher Moritz Schütte.
The battery uses a design without tabs and with two aluminum layers, which reduces resistanceresistance/rɪˈzɪstəns/L2电阻，阻力a force that slows down or opposes the flow of electricity or movement and keeps temperature even. This design is very similar to Tesla's. However, the sodium battery has weaknesses: poor cold-weather charging, uneven copper in the cathode, and lower energy density than lithium-ion batteries.
Sodium is much more abundantabundant/əˈbʌndənt/L2丰富的，大量的existing in large quantities; more than enough than lithium, so it could lower battery costs. If engineers improve cold-weather charging and energy density, sodium will become a cheaper alternativealternative/ɔːlˈtɜːrnətɪv/L2替代品，替代方案something that can be used instead of another thing. However, today's sodium-ion cells have lower energy density and the technology is less maturemature/məˈtʃʊr/L2成熟的fully developed and ready to be used reliably. The researchers will focus on improving low-temperature charging and optimizing materials, such as hard-carbon anodes and electrolytes.
