A single encased electrochemical unit with one positive and one negative electrode is called what?

• A. Battery
• B. Lithium Ion Batteries
• C. Lithium Battery
• D. Battery cell

Answer: (D)

A single encased electrochemical unit with one positive and one negative electrode is a battery cell. A battery is made up of two or more such cells connected together to increase voltage or capacity, so this description points to the individual unit rather than the assembled power source. The options referencing lithium specifically describe a chemistry or a collection of cells, not the single unit itself. Inside a cell, the positive and negative electrodes with electrolyte create the basic electrochemical reaction that produces electrical energy, and when multiple cells are linked, they form a battery.