▎ 摘　　要

NOVELTY - Energy storage device comprises: an anode; a cathode; housing; and an electrolyte comprising a lithium salt, a solvent and a difluorophosphate additive comprising sodium difluorophosphate, where the anode, cathode and electrolyte are positioned within the housing. USE - The device is useful as a battery (claimed), preferably lithium ion capacitor, lithium ion battery or hybrid lithium ion device. ADVANTAGE - The device utilizes the difluorophosphate compounds that significantly improves the lifetime, safety and performance of lithium ion cells, including limiting electrochemical impedance growth, decreasing the rate of self-discharge during storage, increasing cell lifetime, limiting the evolution of gas, decreasing cathode resistance, and/or enhancing cyclability and rate capability. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for fabricating the device comprising positioning the anode, the cathode and the electrolyte within a housing, sealing the housing to form an energy storage device and forming a solid-electrolyte interphase (SEI) at the anode, where forming the SEI comprises charge cycling the energy storage device to a voltage of at least 4.3 V.