Lithium Battery Anodes

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Summary Stanford researchers have designed a novel, pomegranate inspired, hierarchical structure which improves the energy density, cycle life, Coulombic efficiency, and cost efficiency of silicon-based anode for Li-ion, Li-O2 and Li-S batteries.  The prototype successfully demonstrated superior cycle life (1000 cycles with 97% capacity retention), low electrode/electrolyte contact area for improvement of Coulombic efficiency, and increased tap density. Furthermore, unprecedented stable cycling (100 cycles with 94% capacity retention) with high areal capacity (3.7 mAh/cm2), similar to the areal capacity of commercial Li-ion batteries have been achieved. The successful design principles developed here can be widely applied to other high-capacity Li battery electrodes.   Applications Li-ion, Li-O2 , and Li-S batteries with high energy density, long cycle life, and low cost Electric vehicles Portable electronic devices   Advantages Advantages compared to existing Si-based anode materials: Long cycle life at high mass loading (>3 mAh/cm2) Wrapped secondary particles, low contact area with electrolyte, high 1st CE Secondary particles with close packing, high tap density Low-cost and scalable fabrication Does not use expensive Si precursors or reagents during fabrication process Close-packing secondary particles Design innovations: Internally accommodated volume expansion Spatially confined solid-electrolyte interphase (SEI) formation Close-packing secondary particles