Using copper leads to carry electricity between room and liquid helium temperatures would create heat and evaporate the liquid helium that cools the energy storage device.
(the liquid helium; cools; the energy storage device) (Using copper; leads; to carry electricity between room and liquid helium temperatures) (room and liquid helium temperatures; would create; heat)
the liquid helium Using copper room and liquid helium temperatures
cools leads would create
the energy storage device
to carry electricity between room and liquid helium temperatures
heat