A lithium battery with high energy density comprises an insulating corrosion-resistant shell, and a connecting layer is arranged between that insulate corrosion-resistant shell and a positive electrode cover plate or a negative electrode cover plate, which are sealingly and integrally connected by welding or adhesive bonding. The insulating corrosion-resistant shell is connected with a positive electrode cover plate or a negative electrode cover plate. A metal conductive shell is replace by an insulating corrosion-resistant shell, Insulation at the output of the positive and negative electrodes of the lithium battery, sealing and securing connections have revolutionized simplification, In the prior art, the conductor coil, the positive electrode connecting coil, the connecting coil bracket, the special shaped insulation seal and the insulation isolation pad are omitted, so that the height size of the coil core of the lithium battery is increased by 10% to 20%, and the energy density ofthe lithium battery is greatly improved under the condition that the external size of the existing lithium battery is unchanged. At the same time, the production process of the lithium battery is simplified, the production cost is reduced, and the sealing, insulation and corrosion resistance of the battery are more reliable.