Predictive Modeling of End-of-Life Electric Vehicle Battery Volumes and Environmental Impact in Sri Lanka

Abstract

Sri Lanka's electric vehicle (EV) fleet has

grown through a volatile policy history: a tax-concession- driven boom in 2015, a sharp decline after the 2018

budget reforms, near-total suspension under the 2020– 2025 vehicle import ban, and an explosive rebound after the ban was lifted in February 2025. This paper develops a quantitative forecast of end-of-life (EOL) EV battery volumes and associated environmental risk for Sri Lanka, using Weibull survival models combined with Material Flow Analysis (MFA), run separately for Motor Cars and Motor Cycles and resolved by battery pack model and cathode chemistry. Using Department of Motor Traffic (DMT) registration data for 2012–2025 and pack-level lifetime parameters adapted to Sri Lanka's hot climate, the model projects EOL battery volumes and hazardous material load through 2040 under three end-of-life management scenarios. Results show that Motor Cycles dominate unit counts (about 96% of retiring batteries by 2040), while Motor Cars carry 82% of the hazardous load of vehicles already registered; once projected registrations are included, Motor Cycles carry 54% of the hazardous load and about half of the 2025 car cohort remains in service in 2040. The first wave, already under way since about 2018, consists mainly of manganese-rich Nissan Leaf packs, and lithium iron phosphate (LFP) becomes the majority of retiring mass from 2031.

Cumulative hazardous material released under Business- as-Usual conditions is projected at approximately 4,425

metric tons by 2040 (3,067–6,041 t across lifetime cases), falling by 85% under an Aggressive Intervention scenario. The paper concludes with policy recommendations for Sri Lanka's Central Environmental Authority and Department of Motor Traffic.