Batteries are the most expensive component of an electric car. At the end of their service life in electric vehicles, the retired batteries could still retain 40 - 50% of their initial capacity. Recycling is necessary in the end but before that, giving those retired but still capable batteries a 'second-life' in less-demanding applications such as stationary energy storage not only improves material efficiency, but also has the potential to bring tremendous value to a wide range of stakeholders across the automotive and energy sectors, as well as to the society and environment.