The development of cobalt-free high-energy lithium-ion batteries by American universities can greatly reduce battery costs.

SMM: because of the high cost of cobalt and a variety of human rights issues involved in mining, researchers have been looking for ways to remove cobalt from high-energy batteries for decades. However, some attempts in the past have not made cobalt-free batteries meet the performance standards of cobalt-containing batteries.

According to foreign media reports, researchers at the Cockrell School of Engineering at the University of Texas at Austin said that they have cracked the password of cobalt-free high-energy lithium-ion batteries, which not only removes cobalt, but also reduces battery production costs. at the same time, it also improves the performance of some aspects of the battery. The team developed a new type of cathode, an electrode that usually contains cobalt, which is fixed by a component high in nickel. The cathode contains 89% nickel, and other key ingredients are manganese and aluminum.

The more nickel in the battery, the more energy it can store. Increasing the energy density can extend the battery life of mobile phones or the mileage of electric vehicles.

In general, an increase in battery energy density will lead to a decline in other aspects of battery performance, such as a shorter cycle life, that is, the number of times the battery can be recharged and discharged before it fails and can no longer be recharged. The removal of cobalt usually slows down the kinetic reaction of the battery, resulting in a low rate of charge and discharge, that is, the rate of cathodic charge and discharge. However, the researchers say the problems of short cycle life and low charge and discharge rates of cobalt-free batteries have been overcome by finding an optimal metal combination to ensure a uniform distribution of ions.

The cathodes of most lithium-ion batteries use metal ion combinations, such as Ni-mn-Co (NMC) or Ni-Co-Al (NCA). The cost of the cathode accounts for about half of the cost of the battery material, and cobalt is the most expensive component, at about $28500 a tonne, which is more expensive than nickel, manganese and aluminum combined, and accounts for 10 to 30 per cent of the cathodes of most lithium-ion batteries.

"Cobalt is the least reserve and most expensive component in the cathode of the battery," the researchers said. We are removing it completely from the battery. "

The breakthroughs made by the researchers can be observed from an atomic point of view. In the process of synthesis, they can ensure that the ions of various metals can be uniformly distributed in the crystal structure of the cathode. The researchers say that when such ions come together, the performance of the battery degrades, a problem that has plagued previously developed cobalt-free, high-energy batteries. By ensuring that such ions are evenly distributed, researchers can avoid loss of battery performance.

"our goal is to use only abundant and inexpensive metals to replace cobalt while ensuring battery performance and safety, and to adopt an industrial synthesis process that can be expanded immediately," the researchers said. "

Several researchers worked with the Office of Technology commercialization at the University of Texas to set up a start-up called TexPower to bring the technology to market. In addition, the researchers received funding from the U.S. Department of Energy, which has been seeking to reduce its dependence on imports of key battery materials.

The industry has begun to promote cobalt-free batteries, most notably Tesla's attempt to remove cobalt from his car batteries. Competition in this area has become increasingly fierce as large government agencies and private companies are committed to reducing their dependence on cobalt. The researchers say they have solved the problems hindering the development of cobalt-free, high-energy batteries by innovating, combining materials correctly and accurately controlling the distribution of materials.

Click to understand and sign up for the 2020 China Automotive New Materials Application Summit Forum.

Please fill in your personal information on the last page and the meeting staff will contact you later!