1. Nickel-cadmium battery

1.1 Introduction

Nickel-cadmium batteries were discovered in Sweden by Waldemar Jungner, who filed a first patent in 1899, which he extended to the USA in 1901. The invention involved nickel hydroxide Ni(OH) ₂ at the positive electrode, a mixture of cadmium and iron at the negative, and an aqueous electrolyte, KOH (potassium hydroxide or potash). The common name, nickel-cadmium battery, is therefore an approximation. Industrial production of nickel-cadmium batteries with flat positive electrodes, based on the above-mentioned patent, began in 1909. The manufacturing principles developed at that time are still valid today for most of them. Their service life is comparable to that of lead-acid batteries (at least 1,000 cycles), but their fast-discharge...