Combining dynamic material flow analysis and life cycle assessment to evaluate environmental benefits of recycling – A case study for direct and hydrometallurgical closed-loop recycling of electric vehicle battery systems.

• Combined LCA and MFA of hydro. and direct recycling routes for a closed-loop battery value from OEM's perspective. • Savings potential of GHG emissions compared to virgin material production for recycling routes and two NMC cathode. • Analysis of admixture ratios of direct recycled cathode active material and choice of allocation method over time. • Obligatory allocation rules of EoL processes for reliable and realizable LCAs are needed to ensure correct accounting. • Technological investigation of admixture ratios for all kinds of recycling processes needed. We conduct a life cycle assessment (LCA) for two recycling processes, a hydrometallurgical and a direct recycling route. Both show ecological benefits compared to production with virgin material (between 2.76–4.55 kg CO2e/ kg battery for NMC111 and NMC811 less greenhouse gas emissions). In contrast to previous works, we combine the LCA results with a dynamic material flow model. This allows the evaluation of the influence on ecological benefits of admixture limits for directly recycled cathode material in a closed-loop recycling system over a time in which the newly produced battery systems and the amount of end-of-life traction batteries grows. We show that for such a closed-loop recycling system, the choice of different allocation methods, namely cut-off or avoided burden approach, may lead to significantly varying results of up to 85% in ecological benefits. We further conclude that combining production with both recycling routes can achieve the lowest greenhouse gas emissions for our closed-loop scenarios. [ABSTRACT FROM AUTHOR]