NOVELTY - The device (10) has a lithium ion exchange membrane (16) i.e. electrolyte, positioned between a volume (20) for receiving liquid reactant material of a negative electrode (12) i.e. anode, and a volume (22) for receiving liquid reactant material of a positive electrode (14) i.e. cathode. The membrane supports a lithium ion exchange reaction between the materials such that lithium-depleted material of the negative electrode and lithium-enriched material of the positive electrode are obtained. The material of the negative electrode comprises lithium or lithium containing material.    USE - Electrochemical device i.e. rechargeable lithium-ion battery (claimed), for use in a vehicle e.g. hybrid electric vehicle (HEV) such as plug-in HEV, a battery electric vehicle (BEV) or an electric vehicle with extended range (EREV). Can also be used for an electronic device e.g. laptop computer, camera, mobile telephone and smartphone, a military electronics e.g. radio, mine detector and thermal weapon, an airplane and/or a satellite.    ADVANTAGE - The device can be tested locally before disconnection of sources for liquid electrode material to determine power and capacitance of the device for determining whether the device is sufficiently recharged.    DETAILED DESCRIPTION - The lithium ion exchange membrane is formed from polymer, lithiumphosphoroxynitride, lithium sulfide glass, glass-polymer composites or glass-ceramic composites. An INDEPENDENT CLAIM is also included for a method for manufacturing a rechargeable lithium-ion battery.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a lithium-ion battery with a positive liquid reactant electrode and a negative liquid reactant electrode.    Electrochemical device (10)    Negative electrode (12)    Positive electrode (14)    Lithium ion exchange membrane (16)    Volume for receiving liquid reactant material of negative electrode (20)    Volume for receiving liquid reactant material of positive electrode (22)