The present invention relates to a lithium-ion energy store, comprising an electrode comprising a main section and comprising a measurement section electrically isolated from the main section, a counterelectrode and a separator between the electrode and the counterelectrode, wherein a measurement cell, which forms part of the lithium-ion energy store, comprises the measurement section of the electrode, a counterelectrode measurement section, which is opposite the measurement section of the electrode in relation to the separator, and a section of the separator which is arranged between the measurement sections of the electrode and the counterelectrode measurement section, and a main cell, which forms part of the lithium-ion energy store, the main section of the electrode, a counterelectrode main section, which is opposite the main section of the electrode in relation to the separator, and a section of the separator which is arranged between the main section of the electrode and the counterelectrode main section, wherein the lithium-ion energy store comprises a matching device, by means of which an electrical potential of the measurement section and an electrical potential of the main section can be matched to one another.