Groundbreaking layer offers extended lifespan and greater power storage capacity for lithium batteries
In a significant breakthrough, researchers at the University of MΓΌnster, in collaboration with several Chinese organizations, have developed a novel dual-shell coating for lithium-ion batteries. This innovative design aims to address the challenges posed by lithium-rich cathodes, which are notoriously unstable and prone to issues such as electrolyte breakdown, gradual capacity fade, and cathode instability.
The new coating, named LiF@spinel, is designed to prevent surface damage and improve cycling performance. Transmission electron microscopy and X-ray photoelectron spectroscopy confirm the seamless integration of the two layers. At the core, a spinel layer forms directly on the cathode surface, creating a 3D network for lithium-ion transport. On top, a LiF shield chemically bonded with Ni-F anchors seals the electrode against electrolyte attack.
The LiF@spinel approach combines a spinel buffer for rapid ion movement with a LiF outer layer that blocks corrosive attack. This design offers a practical route to stable, high-energy batteries, addressing the limitations that have plagued lithium-ion batteries, such as reliance on scarce metals like cobalt and nickel, safety risks like overheating and fire hazards, and issues with ultrafast cycling at high C rates.
According to the study, published in Energy Materials and Devices, the dual-shell coating significantly improves the lifespan of lithium-ion batteries. For instance, at 2 C, the coated cathode retained 81.5% of its capacity after 150 cycles, compared with 63.2% for an uncoated sample. Even under ultrafast cycling at 5 C, the dual-shell design held more than 80% of its capacity.
Lithium-ion batteries are widely used in various applications due to their lightweight, rechargeable, and high energy density properties. They are commonly found in electric vehicles, smartphones, and renewable energy storage systems. The development of the LiF@spinel coating could potentially revolutionise these industries by providing more reliable and efficient batteries.
The study was supported by several organisations including the Science Research Project of Hebei Education Department, the National Natural Science Foundation of China, and the Central Government Guided Local Science and Technology Development Project of Hebei Province. With this innovative solution, the future of lithium-ion batteries looks brighter and more sustainable.
