Guest Seminar - Advanced Material Technologies for Secondary Lithium Battery

This presentation begins with a morphological analysis of ultra-high nickel ternary cathode material (NCM90, with Ni content ≥0.90), utilizing structural characterization and advanced artificial intelligence deep learning techniques. After optimization, the ultra-high nickel NCM90 cathode material shows denser primary particles, reduced porosity, enhanced resistance to electrolyte corrosion, and moderate lithium-nickel mixing. LiFePO4 (LFP) batteries are widely used for EVs and electricity storage, in view of their decent energy density, superior inherent safety, and ready availability of raw materials. We propose a new type of designer lithium reservoir (DLR) comprising lithium orthosilicate (Li4SiO4) and elemental sulfur to simultaneously address active lithium consumption by solid electrolyte interphase (SEI) formation and the minor but continuous parasitic reactions that occur at the electrode/electrolyte under extended cycling. The incorporation of a small amount ! of DLR (<3 wt% Li4SiO4@S) results in remarkable cycling stability for LFP/graphite cells. For silicon-tin composite anode has ultra-high specific capacity, this DLR technology is also very effective to solve the problem of large irreversible capacity loss in the first cycle and the ongoing consumption of active lithium at the anode/electrolyte interface necessary to repair SEI damage during extended cycling. Pairing high-energy nickel-rich cathodes with current collectors as anodes presents a compelling strategy to significantly boost the energy density of rechargeable lithium-ion batteries (LIBs). We propose a dual-gradient metal (DGM) layer as an innovative solution to mitigate active Li loss by promoting uniform Li deposition and in-situ formation of a stable SEI. The incorporation of this DGM layer significantly enhances the cycle life and energy density of Ah-level pouch cells.