HYBRID ENERGY PACK

A hybrid energy pack comprises at least one lithium ion battery cell 2 and at least one supercapacitor cell 1 employing an non-flammable electrolyte and is characterised in that the battery cell(s) and supercapacitor cell(s) are interleaved with one another. The lithium-ion battery cells and supercapacitor cells may for example have planar morphologies and may be arranged in an alternating stack. The li-ion cell(s) and the supercapacitor cell(s) may be independently removable from a housing. The electrolyte may be an ionic liquid. The supercapacitor cells may comprise electrodes comprising graphene and/or carbon nanotubes. The hybrid energy pack may comprise circuitry to enable the lithium-ion battery cell(s) to trickle charge the supercapacitor cell(s). The hybrid energy pack may comprise circuitry to enable the the supercapacitor cell(s) to recharge the lithium-ion battery cell(s). The supercapacitor cell(s) may comprise circuitry to allow them to be connected to an energy harvesting device which may be integral with the hybrid energy pack. The hybrid energy pack may comprise a heat management circuit connected to the supercapacitor cell(s) for warming or cooling the li-ion cell(s). The flow of the electrolyte within or between supercapacitor cell(s) may be used for thermal management of the hybrid energy pack.