Breakthrough in Salt Lake Lithium Extraction Technology by Nanjing University Researchers
TapTechNews September 28th news, TapTechNews learned from Nanjing University that Professor Zhu Jia and Academician Chen Jun of the university and their collaborators have made important breakthroughs in the field of green development of salt lake lithium resources.
This work successfully developed the interfacial photothermal salt lake lithium extraction technology by imitating the "selective absorption - storage - release" mechanism of halophytic plants. This technology uses the interfacial photothermal transpiration effect to strengthen the mass transfer in nano-channels and drive high-precision ion separation, achieving highly selective, low-energy consumption, and low-carbon emission solar salt lake lithium extraction.
This technology is expected to promote the green development of salt lake lithium resources in Qinghai-Tibet of China and reduce the dependence on imported lithium ores, ensuring the safe supply of strategic key metal lithium. The relevant research results were titled "Solar transpiration-powered lithium extraction and storage" and were published in the Science journal on the 27th.
Salt lake-type lithium ore is an important source of global lithium resources, and China's Qinghai-Tibet Plateau also has extremely rich salt lake resources with huge lithium ore reserves. However, due to the complex chemical conditions of salt lakes and extremely high requirements for environmental protection, the local lithium ore resources have been difficult to mine and utilize on a large scale so far, which has become a "bottleneck" problem in China's lithium ore mining. Developing green, environmentally friendly, and sustainable new salt lake lithium extraction technologies is the key to solving this problem.
In nature, life systems such as halophytic plants have the ability to efficiently extract specific substances. Halophytic plants can use transpiration to selectively absorb salt and water from saline-alkali environments and store and excrete excess salt in specific organs, forming a " selective absorption - storage - release" mechanism, enabling them to maintain normal metabolism and growth in extremely saline-alkali environments, providing an important bionic inspiration for developing efficient and sustainable salt lake lithium resource extraction technology.
Inspired by this, the research team of Nanjing University successfully developed an interfacial photothermal salt lake lithium extraction device, mainly including the following three parts:
The interfacial photothermal transpiration generates extremely high capillary pressure in the evaporator nano-channel (Figure 1C);
This capillary pressure is transmitted to the ion separation layer (Figure 1E), driving the selective entry of lithium ions from brine into the storage layer;
Collect the enriched lithium salt in the storage layer (Figure 1D) through the water circulation system and realize the regeneration of the device.
According to the introduction, the research team built an interfacial photothermal salt lake lithium extraction platform (Figures 2A-2C), comprehensively evaluated its salt lake lithium extraction performance (Figures 2D-2E), and tested the lithium extraction effect of this device in salt lake brine. The results showed that this platform can efficiently extract lithium from diluted salt lake brine (Figure 2F). Thanks to its renewable ability, the device showed e xcellent stability during 528 hours of continuous operation (Figure 2G), thus demonstrating its great potential in long-term applications.
The interfacial photothermal salt lake lithium extraction device also has good compatibility and scalability. By optimizing the ion separation layer, the lithium selectivity of a single-stage device increased by 6 times; through a multi-stage lithium extraction process, the lithium selectivity can be increased by nearly 40 times. The modular design endows the system with good expansion ability, and the lithium production increases linearly with the number of modules, fully demonstrating its potential in large-scale applications.