The reporter learned from Nanjing University that Professor Zhu Jia and Academician Chen Jun of Chinese Academy of Sciences successfully extracted high-purity lithium salt from Salt Lake brine efficiently and environmentally friendly by imitating the transpiration process of saline soil plants, it is expected to help the green and high-quality development of lithium industry in plateau salt lakes in China. The international academic journal Science published relevant results on 27th.

According to Song Yu, the first author of the paper and the special associate researcher of Nanjing University, electric vehicle battery lithium, the key mineral in energy storage materials, mainly exists in two forms: Salt Lake brine and solid ore. There are many salt lakes distributed in the Plateau area of our country, with abundant lithium resources, but the key index of "magnesium-lithium ratio" of the lake water is relatively high, which makes it difficult to separate magnesium and lithium, the lithium salt produced has high cost and low quality. The ecology of plateau area is fragile, and strict environmental protection requirements are also put forward for related industries.

The scientific research team of Nanjing University thought that in saline-alkali environment, saline soil plants can selectively absorb salt and water through transpiration. By imitating the principle of transpiration, the team successfully developed the "interface photothermal" Salt Lake lithium extraction device ". The device is divided into three layers. Under sunlight, ultra-high pressure is generated in the nano channel of the evaporator, and high pressure is transferred to the ion separation layer, which will selectively "drive" the lithium ions in brine to the storage layer, finally, the lithium salt in the storage layer is collected through the water circulation system.

Song Yi told the reporter that in the day-night alternation of laboratory simulation and Salt Lake brine environment, the device has been running continuously for 528 hours, and the "magnesium-lithium ratio" of brine has dropped from the initial value 422 to 2.5, the purity of lithium is increased by more than 160 times, which verifies the feasibility and high efficiency of the whole device.

Zhu Jia said that through modular assembly and combination, the area of the device can be continuously expanded, thus increasing the output of lithium salt. "More importantly, the device can be operated by solar energy without consuming additional electricity and chemicals. It is especially suitable for application in plateau areas with abundant light resources but fragile ecological environment, with low energy consumption, it is also environmentally friendly."

it is understood that the team plans to carry out pilot test and industrialization test on the plateau in the next stage, and further optimize the device according to the different physical and chemical characteristics of various salt lakes on the plateau.Design and strive to form a practical production line of Salt Lake lithium mine as soon as possible with the support of many parties.