Technology, economic, and environmental analysis of second-life batteries as stationary energy storage: A review

With global warming on the rise, the push for zero-emission transportation continues to grow. The transportation sector’s solution to increasing climate concerns has been to promote electric vehicles (EVs) as a replacement for traditional internal combustion engine (ICE) vehicles. Although the objective of EVs seems obvious, EVs come with an undeniable problem: battery decommission and disposal. EV batteries are required to deliver power so that the vehicle can accelerate quickly and drive extended distances; the battery has to be at a sufficient state of health (SOH) to deliver satisfactory results. Once a battery reduces to a SOH that is no longer adequate, it must be retired from the EV. The significant increase in the number of EVs and their forecasted exponential growth also comes with an accumulation of retired batteries, the handling of which raises serious concerns. However, research reveals promising repurposing that can give retired EV batteries another life as second-life batteries (SLBs). Research to address concerns about performance and cost compared to new batteries in various applications, under a variety of conditions, is ongoing. In addition, environmental assessments are being conducted to justify this innovative technology. This review paper outlines the current literature and most recent findings related to these topics and provides a brief comparison of SLBs to new batteries.