R code for: Quantifying the Degradation Cost of Frequent Fast Charging Across Multiple Electric Vehicle Battery Chemistries

Abstract (Article) We investigate the relative impact of fast charging on degradation in commercial lithium-ion battery cells with electric vehicle-relevant chemistries (NMC, NCA and LFP) by cycling them under five different repeating patterns that mix fast and slow charging events for up to 16 months with passive thermal management. We then estimate pack replacement cost to reach 150,000 lifetime vehicle miles traveled. We find that more fast-charging results in more degradation, but the magnitude of this effect varies considerably across the tested chemistries. For the most extreme scenario (>90% fast charging, full voltage range), we find average pack replacement costs span from $0 for LFP (no replacements) to $32,000 for NMC (3 replacements) and $210,000 for NCA (20 replacements). Restricting fast charging voltage to cycle ~20% to 80% of nameplate capacity reduces lifetime pack replacement costs to $0 for NMC and $60,000 for NCA (6 replacements). These degradation patterns suggest that when operating to limit capacity fade from fast charging there are cases where the practical energy density of LFP packs can exceed that of NMC and NCA packs.