At the end of its useful life in a vehicle, a lithium-ion battery will have approximately 80% of its capacity remaining. The battery’s fate at that point is the subject of much discussion and debate. Battery companies, OEMs, universities, and National Labs are all exploring the optimal options to ensure a closed-loop lifecycle and therefore minimal environmental impact. These include both second-use and recycling.
Second-use
After its useful life a battery may no longer be relevant to move a vehicle, but there could be a second use to which it could be deployed. “Second-use” applications could significantly increase the total lifetime value of the battery, and thus reduce its cost to the automotive user. Second-life applications include the following:
Grid-based stationary (e.g. energy time-shifting, renewables firming)
To date, 24 US States have Renewable Portfolio Standards in place. These standards are amplifying the adoption of renewable energy on the grid. Renewable energy, namely wind, will increase the intermittency and variability of electricity, driving the necessity of more stationary storage. As batteries conclude their primary use in vehicles it is possible that they will be employed to facilitate the large amount of renewable energy on the grid.
Off-grid stationary (e.g. backup power, remote installations)
Community and Residential Energy Storage systems are relatively small KWh systems that provide back-up storage to a number of households. As more electric vehicles need to be charged, more off-grid storage may be necessary. Electric vehicle batteries that have achieved their useful life in that application may be well suited, for community storage as they share the same form factor as these smaller storage systems.
Mobile stationary (e.g. auxiliary PTO systems)
Fleets may consider replacing their generators and lead-acid batteries with second-life lithium ion batteries, to support anti-idling. The duty cycle of auxiliary systems is rather light and likely a good fit for batteries with less capacity.
There are currently many factors which must be taken into account as a second-life market is developed. They include:
- The rate at which a battery degrades after 80% capacity;
- The cost of refurbishing and integrating batteries;
- Quick pace of development of competing technologies for renewable energy storage;
- Lack of a clear logistics and distribution channel to collect batteries after their primary life;
- Lack of market mechanisms and presence of regulation.
NREL, Nissan, Oak Ridge, and ABB/General Motors are exploring some of these issues.
Recycling
Battery recycling has been employed for close to 100 years. Many of the same processes employed in primary battery recycling can be replicated for lithium-ion battery recycling. Indeed, several recycling companies are already collecting and recycling lithium-ion batteries. Depending on the metals employed in the battery, the value generated from recycling can exceed the cost. Additionally, as metals become scarcer, the industry will advance more boldly into recycling, reclaiming, and reusing battery material.
In the absence of federal regulation in the United States, the lithium ion battery recycling market is still early to develop. The key obstacle is the lack of clarity regarding responsibility (i.e. who is responsible to collect and recycle batteries – the battery company or the OEM). In Europe, there is clear legislation which has resulted in the establishment of a logistics and distribution channel to collect and recycle batteries after their useful life. The PRBTA and the USABC have both established industry working groups to advance this issue.
Future scenario for battery “End of Life”:
