High Energy, High Power, Long Cycle Life Silicon Anodes for Li-ion Batteries at Low Cost скачать в хорошем качестве

High Energy, High Power, Long Cycle Life Silicon Anodes for Li-ion Batteries at Low Cost

Abstract: Silicon as a promising anode material for next-generation Li-ion batteries (LIBs) has attracted tremendous attention and investigation due to its extremely high specific capacity, low lithium-alloying voltage, and abundant amount on earth. However, practical applications of Si are impeded by its low intrinsic electrical conductivity of Si and huge volume expansion during lithiation. To address these challenges, nanoscale Si has been utilized to minimize volume expansion per particle during lithiation and to circumvent its low conductivity by connecting nano-Si to a conductive network. However, the use of Si nanoparticles is not only expensive, but also not sufficient for performance because the repeated volume expansion and shrinkage during charge/discharge result in repeated SEI layer fracture and formation that consume Li ions and deteriorate the electrolyte. Embedding engineered void space inside nano-Si particles in conjunction with a conductive shell can provide a solution to all the key technical problems faced by Si anodes. This presentation highlights a novel synthesis method that starts with commercially low cost, micron-sized Si powder and uses industry-scale high-energy ball milling with environmentally benign NaOH solution to create engineered void space inside the nanostructured Si core encapsulated by a conductive carbon shell. The Si micro-reactor particles derived from this novel manufacturing method not only are low cost (only one third of graphite anodes on the energy base, $/kWh), but also exhibit unusual electrochemical properties with specific capacities of 1,300 mAh/g Si at the current density of 1 A/g Si and 780 mAh/g at 8 A/g Si, ultrafast charging/discharging capability (6 min to the full capacity at 8 A/g Si), and long cycle life (1,000 cycles). The high-performance Si micro-reactor anode material produced via this facile and industrially scalable manufacturing method at low cost will pave the way for widespread acceptance of electric vehicles (EVs) by consumers, making EVs more affordable and society greener and sustainable. Keywords: Silicon anode; Li-ion batteries; high capacity; high power; long cycle life. Full Article: https://www.proceedings.iaamonline.or...