  Cyclic voltammetry (CV) is a powerful technique for characterizing
electrochemical properties of electrochemical devices. During
charging-discharging cycles, thermal effect has profound impact on its
performance, but existing theoretical models cannot clarify such intrinsic
mechanism and often give poor prediction. Herein, we propose an interfacial
model for the electro-thermal coupling, based on fundamentals in
non-equilibrium statistical mechanics. By incorporating molecular interactions,
our model shows a quantitative agreement with experimental measurements. The
integral capacitance shows a first enhanced then decayed trend against the
applied heat bath temperature. Such a relation is attributed to the competition
between electrical attraction and Born repulsion via dielectric inhomogeneity,
which is rarely understood in previous models. In addition, as evidenced in
recent experimental CV tests, our model predicts the non-monotonic dependence
of the capacitance on the bulk electrolyte density, further demonstrating its
high accuracy. This work demonstrates a potential pathway towards
next-generation thermal regulation of electrochemical devices.
