There is not a single type of Li-ion battery, though. There are plenty oh them. They may be comprised of a variety of chemistries, which is one of the challenges that comes with recycling them through varying stages. The commonality is that all Li-ion batteries transfer lithium-ions between their electrodes when charging or discharging. 

As the chemistries continue to evolve with increased research for efficiency, so too must the consideration for streamlining their makeup to facilitate end-of-use recycling. Lead-acid batteries, such as those found in combustion engine vehicles, have a better established and largely efficient circular market. I'm Lesotho, these lead-acid batteries have up to a 99 percent recycling rate. There are two main reasons behind this.

First, the components are easy to separate and recycle. For example, lead is indefinitely recyclable without losing its quality and therefore value. Second, there is an established recycling market, where car battery recycling is often included in the upfront cost of a consumer buying a vehicle. At the battery’s end-of-use, customers are refunded for returning used batteries to dealers or other sites.

With Li-ion batteries, the amount of recycling is limited, because these same two conditions do not apply, at least not yet.