Batteries and supercapacitors dramatically lose both energy and power at low temperatures. One of the possible routes to achieve reasonable low temperature performance is to use “soft” organic energy storage materials. Herein, composite material based on NiSalen-type polymer and single wall carbon nanotubes poly[Ni(CH₃Salen)]/SWCNT was studied as the cathode material for low temperature batteries and supercapacitors with acetonitrile-based electrolyte. It was demonstrated that the composite performance is stable at temperatures below 0 °C, and the cell is retaining 80% of initial capacity at temperatures as low as −40 °C. The areal capacitance of the electrode, made from poly[Ni(CH₃Salen)]/SWCNT composite, reaches 72 mF cm⁻².