Detailed & Introduction
Li-ion batteries have become an integral part of our lives, powering everything from our mobile phones to electric cars. The demand for high-performance Li-ion batteries is constantly increasing due to the fast-growing electric vehicle market. However, Li-ion batteries are expensive and can degrade over time, leading to a decrease in their capacity. To address this issue, a team of researchers at the East China University of Science and Technology (ECUST) has developed a unique strategy to make Li-ion batteries cheaper and better. They have found a way to increase the stability of nickel-rich cathode in Li-ion batteries, which could give rise to more advanced high-energy Li-ion batteries.
Components of Li-ion batteries
Li-ion batteries are made up of four primary components: cathode, electrolyte, separator, and anode. The cathode and anode in the battery are coated with special materials to enhance their stability, conductivity, and energy density.
The researchers at ECUST suggest that coating the cathode with a nickel-rich layer could give rise to more advanced high-energy Li-ion batteries, which will have better electrochemical performance and cost less than currently used Li-ion batteries. However, nickel-coated cathodes are highly unstable and lead to a significant decrease in battery capacity in the long run.
The problem with nickel-rich cathodes
The use of lithium-ion batteries is mainly constrained by the limited specific capacity of their cathode material. Nickel-rich layered cathodes always suffer from rapid capacity fading because of the structural and interfacial instability that occurs with long-term operation.
The current study is not the first attempt to make nickel-rich cathodes work. Scientists have been trying to overcome the stability issues for some time, but most such efforts have been focused on either surface coating or element doping. The study authors believe that such unidirectional methods are not enough to overcome the “structural and interfacial instability” of nickel-rich cathodes.
The researchers proposed a dual-modification strategy that promises to make nickel-rich cathodes stable and feasible in the long run. Their battery cathode comes doped with titanium and coated with a nickel layer containing lithium yttrium dioxide (Li YO2). This dual modification is achieved through a sintering method that applies heat and pressure and turns everything (coating, doped material, and cathode) into a solid mass.
Performance of dual-modified cathode
The researchers tested this cathode using X-ray diffraction and electron microscopy. These tests revealed that the modified cathode was both structurally stable and has better battery capacity retention than a regular cathode. After 100 and 500 charge cycles, the dual-modified cathode had capacity retention of 96.3 percent and 86.8 percent, respectively.
Testing the cathode in extreme conditions
The researchers are now planning to test their dual-modified cathode’s performance in challenging environments. “The stability under extremely harsh conditions will be studied to ensure the safety of the material and facilitate its commercial application,” Hao Jiang, one of the study authors and a professor at ECUST, said in a press release.
Scalability of the process
Professor Jiang and their team also aim to make this process scalable so that batteries with the dual-modified cathode could soon become commercially available.
The dual-modification approach developed by the researchers at ECUST is a significant breakthrough in the field of Li-ion batteries. This approach has the potential to make Li-ion batteries cheaper and better, which will benefit both consumers and the environment. With further testing and commercialization, Li-ion batteries with nickel-rich cathodes could become a reality in the near future.