New breakthrough in lithium battery recycling! New technologies reduce energy consumption by 90% and greenhouse gas emissions by 75%

SMM: most lithium batteries today use the rare and expensive metal cobalt as part of their cathodes, but mining this material brings huge costs to the environment. Therefore, scientists have been trying to find more environmentally friendly alternative materials, and lithium phosphate ion is one of them. It is reported that the latest research can further improve its environmental performance, and once it is used up, it can be restored to its original state with a little energy.

The study, conducted by nanoengineers at the University of California, San Diego, focused on the recycling of cathode batteries made of lithium iron phosphate. By reducing heavy metals such as nickel and cobalt, these types of batteries can help avoid the degradation of mining landscapes and water sources, while preventing workers from being exposed to dangerous conditions during mining.

Growing awareness of cobalt-related issues is transforming the industry, with many looking for alternatives to battery design, including big companies such as IBM and Tesla. This year, Tesla began selling Model 3, which uses lithium iron phosphate batteries. These batteries are safer, have a longer life and have lower production costs, but one of the disadvantages is that once they are used up, the recycling cost is high.

"it's not cost-effective to recycle them," said Zheng Chen, a professor of nanoengineering at the University of California, San Diego. "it's the same dilemma as plastics-materials are cheap, but ways to recycle them are not cheap."

The breakthroughs in this study mainly focus on several mechanisms behind the performance degradation of lithium iron phosphate batteries. When they are recycled, this process promotes structural change, with the loss of lithium ions, vacancies are created in the cathode, and iron and lithium ions exchange positions in the crystal structure. This traps lithium ions and prevents them from circulating in the battery.

The team used the commercially available lithium iron phosphate battery and consumed half of its storage capacity. They then took the battery apart, soaked the resulting powder in a solution containing lithium salts and citric acid, then washed it, dried it, and heated it at a temperature of about 60 to 80 °C. The powder was then made into a new cathode and tested in button and pouch batteries, and the team found that its performance returned to its initial state.

The researchers point out that this is because this recycling technology can not only replenish the lithium ion reserve of the battery, but also return the lithium ion and iron ion to their original position in the cathode structure. This is due to the addition of citric acid, which provides electrons for iron ions and reduces the positive charge that prevents iron ions from moving to their original position. As a result of all this, lithium ions can be released and recycled through the battery again.