1. NiCd batteries

Nickel-cadmium (NiCd) batteries were invented in 1899 by the Swede Waldmar Jungner, and have been in production since 1910. Their performance, better than that of lead-acid batteries, led to their more widespread use from 1960 onwards, albeit limited by their higher price. Today, they are still used because of their remarkable durability and reliability, despite their energy density, which remains modest compared with that of other more recent technologies (in particular lithium batteries). However, due to the toxicity of cadmium, their use has been banned in Europe since 2006 (European Parliament directive 2006/66/EC), except for emergency and alarm systems, notably emergency lighting, and medical equipment. In particular, this allows these batteries to be used in the telecommunications, rail and defense sectors. The use of NiCd batteries in power tools has been banned since December 31,...