= Solution
A \b[<primary battery>] is intended for a single discharge; a \b[<secondary battery>] is designed for repeated electrical recharge through sufficiently reversible reactions. A \b[<microbattery>] is defined by its small dimensions or microfabricated construction, not by rechargeability. Therefore microbatteries can belong to either class. A thin-film Li-ion <microbattery> with reversible insertion <electrodes> is secondary because lithium can shuttle back and forth during discharge and charging; a miniature cell using irreversible primary chemistry remains primary. \b[Small size alone does not justify assigning every <microbattery> to the secondary class.]
Back to article page
