Fig. 2

Dynamics of energy storage. The system is initially prepared at thermodynamic equilibrium where \([{\mathrm{M}}]_{{\mathrm{eq}}} \gg [{\mathrm{A}}_2]_{{\mathrm{eq}}}\). At time t = 0, the chemical potential difference between fuel and waste is turned on at \({\cal{F}}_{{\mathrm{fuel}}} = 7.5 \cdot RT\) and drives the system away from equilibrium. After a transient (charging phase), the system eventually settles into a nonequilibrium steady state (maintenance phase). a Species abundances. b Energy stored, work and efficiency (right axis, adimensional units). Kinetic constants ({k_±ρ}) and chemical potentials used for simulations are given in Supplementary Table 1