An energy storage device, comprising: an electrical module, wherein the electrical module comprises an electrical cabinet provided with a receiving cavity; battery modules, wherein a number of the battery modules is two, the electrical module is sandwiched between the two battery modules, and the two battery modules respectively cover both ends of the receiving cavity; and first sealing members, wherein the first sealing members are arranged around the receiving cavity, and the first sealing members are respectively pressed between the battery modules and the electrical module to seal the receiving cavity; wherein each of the battery modules comprises a box, a cover plate, a cell and a second sealing member, the box is provided with an accommodation cavity, the cell is accommodated in the accommodation cavity, the cover plate is provided on the box and caps the accommodation cavity, the second sealing member is arranged around the accommodation cavity, and the second sealing member is pressed between the cover plate and the box to seal the accommodation cavity; each of the battery modules further comprises a liquid cooling plate connected to the box and used to cool down the cells, and the cell is placed naked in the accommodation cavity and share the liquid cooling plate; each of the battery modules further comprises a fixing member, a first liquid cooling connector and a first electrical connector, the fixing member is connected to the box and is located in the accommodation cavity, the first liquid cooling connector and the first electrical connector are both arranged on the fixing member, the first liquid cooling connector is connected to the liquid cooling plate and the electrical module, and the first electrical connector is electrically connected to an electrode of the battery module and to the electrical module. an electrical module, wherein the electrical module comprises an electrical cabinet provided with a receiving cavity; battery modules, wherein a number of the battery modules is two, the electrical module is sandwiched between the two battery modules, and the two battery modules respectively cover both ends of the receiving cavity; and first sealing members, wherein the first sealing members are arranged around the receiving cavity, and the first sealing members are respectively pressed between the battery modules and the electrical module to seal the receiving cavity; wherein each of the battery modules comprises a box, a cover plate, a cell and a second sealing member, the box is provided with an accommodation cavity, the cell is accommodated in the accommodation cavity, the cover plate is provided on the box and caps the accommodation cavity, the second sealing member is arranged around the accommodation cavity, and the second sealing member is pressed between the cover plate and the box to seal the accommodation cavity; each of the battery modules further comprises a liquid cooling plate connected to the box and used to cool down the cells, and the cell is placed naked in the accommodation cavity and share the liquid cooling plate; each of the battery modules further comprises a fixing member, a first liquid cooling connector and a first electrical connector, the fixing member is connected to the box and is located in the accommodation cavity, the first liquid cooling connector and the first electrical connector are both arranged on the fixing member, the first liquid cooling connector is connected to the liquid cooling plate and the electrical module, and the first electrical connector is electrically connected to an electrode of the battery module and to the electrical module.