A clutch mechanism for an energy storage device, comprising a load gear, a drive gear, a one-way bearing, a bushing and a gear shaft comprising a gear portion and a clutch portion, wherein the load gear is connected coaxially to the bushing via the one-way bearing so as to be rotatable in a single direction, the bushing is connected coaxially to the clutch portion so as to be rotatable in two directions, and the drive gear is externally meshed with the gear portion; the gear shaft comprises multiple cylinders, and a push rod, a rotary sleeve and an elastic element located in a cavity of the gear shaft, wherein the clutch portion has multiple holes corresponding to the cylinders, with the cylinders being located in the holes, and at the junction of the gear portion and the clutch portion there is a gear shaft connecting hole; the rotary sleeve has two rotary sleeve slide holes (311, 312) which extend spirally in an axial direction, and has multiple sleeve slots corresponding to the cylinders, the two rotary sleeve slide holes (311, 312) being centrosymmetric around the axis of the rotary sleeve, and an inside wall of the bushing having multiple bushing slots corresponding to the cylinders; the push rod comprises a push rod slide hole and a push rod connecting hole and can slide axially, wherein one end of the push rod passes through the rotary sleeve and presses the elastic element, and the push rod is connected to the gear shaft by a guide pin which passes through the push rod slide hole and the gear shaft connecting hole, and connected to the rotary sleeve by another guide pin which passes through the push rod connecting hole and the two rotary sleeve slide holes (311, 312); a press block is fixed to the drive gear, the press block being capable of contacting the other end of the push rod and pushing the push rod to slide axially; when the press block pushes the push rod, the cylinders are released so as to unlock the bushing from the gear shaft; when the press block leaves the push rod, the cylinders are clamped between the rotary sleeve and the bushing so as to lock the bushing to the gear shaft. the gear shaft comprises multiple cylinders, and a push rod, a rotary sleeve and an elastic element located in a cavity of the gear shaft, wherein the clutch portion has multiple holes corresponding to the cylinders, with the cylinders being located in the holes, and at the junction of the gear portion and the clutch portion there is a gear shaft connecting hole; the rotary sleeve has two rotary sleeve slide holes (311, 312) which extend spirally in an axial direction, and has multiple sleeve slots corresponding to the cylinders, the two rotary sleeve slide holes (311, 312) being centrosymmetric around the axis of the rotary sleeve, and an inside wall of the bushing having multiple bushing slots corresponding to the cylinders; the push rod comprises a push rod slide hole and a push rod connecting hole and can slide axially, wherein one end of the push rod passes through the rotary sleeve and presses the elastic element, and the push rod is connected to the gear shaft by a guide pin which passes through the push rod slide hole and the gear shaft connecting hole, and connected to the rotary sleeve by another guide pin which passes through the push rod connecting hole and the two rotary sleeve slide holes (311, 312); a press block is fixed to the drive gear, the press block being capable of contacting the other end of the push rod and pushing the push rod to slide axially; when the press block pushes the push rod, the cylinders are released so as to unlock the bushing from the gear shaft; when the press block leaves the push rod, the cylinders are clamped between the rotary sleeve and the bushing so as to lock the bushing to the gear shaft.