University of Pittsburgh researchers have developed a novel approach to producing high-energy lithium metal batteries. Innovative iron, aluminum, and magnesium multicomponent alloys (MCA), with or without soluble metallic lithium, can act as anodes or anode-free current collectors. These lightweight materials could replace copper current collectors used in lithium battery technologies, substantially lowering the battery weight and revolutionizing the design of Li metal battery anodes.
Description
Metallic lithium is ideal for high-capacity batteries with a theoretical capacity of ~3861 mAh/g. However, metallic lithium regularly forms pernicious dendrites which can lead to short circuits causing overheating and fires. There is a need to develop novel anodes to prevent the formation of these dendrites and allow production of higher capacity lithium-ion batteries. This approach uses novel MCA alloys to produce lithium batteries with capacities identical to Li metal without forming dendrites, leading to safer and lighter alternatives to existing technology.
Applications
• High-capacity lithium-ion batteries
• Safer lithium batteries
Advantages
Current lithium-ion batteries rely on strategies to reduce, minimize and eliminate the formation of dendrites. These include polymeric coatings, inorganic and metallic films as well as porous metal structures to create uniform Li metal disposition. While these reduce the risk of short circuits and fires occurring, they increase the weight of the batteries and lower the electrical densities. This novel approach uses innovative MCA alloys that can act as an anode (when containing Li) and current collector (without Li), reducing the weight of the battery compared to existing approaches that have separate anodes and current collectors. Additionally, unlike copper current collectors or metallic Li foil anodes commonly used in Li batteries, MCA alloys prevent dendrite formation even after many hundreds of cycles. Finally, these improved Li batteries have increased gravimetric and volumetric capacity compared to existing approaches.
Invention Readiness
Various MCAs were investigated and found to form a body-centered cubic crystal structure isostructural to metallic Li. These lightweight alloys had densities >50% of copper and exhibited a solubility limit of metallic Li as high as 62 atomic %, resulting in solid solution alloy formation causing up to 18 mAh/cm2 of areal capacity of Li (~100 microns of Li) to be alloyed with the MCA system. These batteries had identical capacity to Li metal alone (3861 mAh/g). Testing found anode and current collectors could undergo hundreds of cycles without dendrite formation or loss in performance. Work is required to optimize and further study this approach including scale up and full cell fabrication.
IP Status
https://patents.google.com/patent/WO2025043089A1
