Published on August 17th, 2016 | by James Ayre0
Reducing Propensity For Electrode Fragmentation In Silicon-Aluminum Anodes For Lithium-Ion Batteries
Researchers from the University of Windsor in Ontario have discovered a new means of improving silicon anode durability (when in use with lithium-ion batteries) through the utilization of newly observed self-healing behavior of cracks in micron-sized silicon particles dispersed “in a ductile Al matrix cycled using a high lithiation rate of 15.6 C.”
As some of those reading this will be aware, a major issue with the use of high-capacity silicon anodes in rechargeable lithium-ion batteries is lithiation-induced volume changes in silicon — which results in the fracture and fragmentation of the anode material, and thus with a loss of energy storage capacity.
The new findings — which are detailed in a paper published in the Journal of Power Sources — mean that a potential pathway towards the development of more durable silicon battery anodes has been found.
The research paper stated: “By electrochemically cycling these electrodes vs. Li/Li+, crack formation and growth in Si particles during the lithiation/de-lithiation cycles were monitored using analytical microscopy and surface characterization techniques. An interesting self-healing process occurred and consisted of arresting of cracks formed in Si particles by the Al matrix, and closure of cracks during de-lithiation.”
The conclusion offered by the researchers was: “In summary, composite electrode materials consisting of uniformly distributed Si embedded in a ductile and inert phase having high fracture toughness could reduce the propensity for electrode fragmentation and improve battery electrode durability.”
As with all battery-related research, a grain of salt is advised — what goes on in a lab may or not be economically viable, or repeatable for that matter.