This research offers a promising path forward for next-generation cathode development, paving the way for more durable and efficient lithium-ion batteries critical to electric vehicles and energy storage systems.
A research team at Pohang University of Science and Technology has unveiled strategy to significantly improve the durability of lithium-rich layered oxide (LLO) materials, a next-generation cathode for lithium-ion batteries (LIBs). This advancement could extend battery lifespans and enhance their viability for commercial applications.
LLO materials are gaining attention for their ability to deliver up to 20% higher energy density than conventional nickel-based cathodes. LLO offers a more economical and sustainable alternative by increasing lithium and manganese content while reducing nickel and cobalt. However, issues like capacity fading and voltage decay during charge-discharge cycles have limited its adoption.
While previous studies linked these problems to structural changes in the cathode, the exact causes remained unclear. Efforts to stabilize LLO have struggled to address the root causes, slowing progress toward commercialization.
The research team focused on oxygen release during charge-discharge cycles as a key destabilizing factor. They hypothesized that enhancing the chemical stability of the cathode-electrolyte interface could curb oxygen release. By optimizing electrolyte composition, they successfully reinforced this interface, significantly reducing oxygen emissions and improving battery performance.
Tests showed the enhanced electrolyte achieved an impressive energy retention rate of 84.3% after 700 cycles. In comparison, conventional electrolytes retained just 37.1% energy after 300 cycles. The team also addressed structural changes on the LLO surface, which were found to impact overall material stability. These improvements not only extended cathode lifespan but also minimized issues like electrolyte decomposition.
The team emphasized the importance of surface stability, explaining, using synchrotron radiation, they analyzed the chemical and structural differences between the surface and interior of cathode particles. This revealed that surface stability is crucial for maintaining the structural integrity and performance of the material.
