Fig. 1From: Tractable lithium-ion storage models for optimizing energy systemsaM function, which maps the applied current and energy content to a unique voltage, shown with blue curves obtained from a spec and grey points representing the interpolated surface between the curves. b a1(.) and a2(.): points obtained from the spec. c ηc(.) and ηd(.), with each line representing the efficiency at a different C-rate, as per Eqs. 7 and 8Back to article page