I am looking to conduct a life cycle analysis (LCA) to investigate the total greenhouse gas (GHG) emission contributions from lithium ion (Li-ion) batteries. The first part of their lifecycle is relatively straightforward. GHGs from raw material extraction, refinement, and cell/pack production (including required energy) are intuitive. The use phase is also somewhat easy to do.
My question is regarding the second life. How does second life application of a Li-ion battery (say... in stationary storage) impact the life cycle emissions? If the battery is used in a stationary storage application, I would imagine this is beneficial to its LCA GHGs. However, how does this mathematically play out? Is it in new battery-manufactured avoidance? Is it in replacement of a more GHG-intensive stationary storage alternative? How do I account for the second life benefit of the battery?