Vehicle drive batteries are subject to the Batteries and Accumulators Directive, but are allowed to include the 'jacket' in order to meet the recycling efficiency target.
Recycling of this outer jacket allows the industry to meet the Directive recycling target (currently set at 50%) without actually recycling the battery cells themselves.
Estimates expect 1 million electric vehicles to be on UK roads by 2020 (www.myelectricavenue.info). If each vehicle contains 5,000 battery cells (18650's), this could mean 5,000,000,000 battery cells being sent to landfill at end of life. If only the outer jackets are recycled, the recycling targets will have been achieved but much valuable material would have been lost.
This waste of critical materials occurs because industry doesn't want to spend money on recycling; recycling is not cheap, and recovery of materials other than those which are abundant (steel, aluminium, nickel, cobalt, and copper) require more sophisticated recycling techniques compared to current pyrometallurgical approaches.
However, batteries contain a plethora of metals, including lanthanides, which have been identified as critical raw materials within Europe. For this reason, a few companies have decided to invest in their own recycling plants, where they create closed loop recycling - old vehicle batteries are recycled and the recovered materials used to create new batteries (e.g. Honda have a plant in Japan (as part of their Triple Zero Approach to sustainability)).