1. Field of the Invention
The present invention relates to a lithium-ion battery, and more particularly, relates to a lithium-ion battery having a passivation protector.
2. Description of Related Art
Much attention has been paid to the rechargeable secondary battery system since the primary battery system cannot meet the requirement of environmental protection. Lightweight batteries are necessary for portable electronic products such as the digital camera, the cell phone, or the notebook. With the rapid development and popularization of portable electronic products, there is gradually increasing demand on the lithium-ion battery, which may be repeatedly charged and discharged and has advantages such as light weight, high voltage, and high energy density. The lithium-ion battery has a higher working voltage, a greater energy density, a lighter weight, a longer lifetime, and executes environmental protection more effectively as compared to the traditional batteries such as the lead storage battery, the nickel-hydride battery, the nickel-zinc battery, and the nickel-cadmium battery. Therefore, the lithium-ion battery is one of the best candidates of the flexible battery. It is thus required to reduce the weight of the lithium-ion battery as well as to improve the durability, the output voltage, the energy density, and the safety of the lithium-ion battery. The application and development potential of the lithium-ion battery is particularly high in industrial fields such as the lightweight electro mobile, the electro mobile, and the large-scale electronic storage.
The so-called secondary lithium-ion battery is a battery in which the lithium ions move between the cathode and the anode to repeatedly charge and discharge the battery. Commercialized secondary lithium-ion batteries generally adopt meso carbon micro bead (MCMB) as the host of the anode material. In the initial cycle of charge and discharge, the surface of MCMB reacts with the electrolyte to form a solid electrolyte interface (SEI) on the anode. The solid electrolyte interface may prevent the disintegration of the surface of the anode material as well as prevent the decomposition of the electrolyte, and thus stabilize the cycle of charge and discharge. Therefore, the solid electrolyte interface has critical influence on the lifetime of the battery.
In recent years, with the application of lithium-ion battery to energy storage systems and vehicles operated with novel energy source, the market scale of the lithium-ion battery in electro mobile and power battery industries has gradually increased. Therefore, it is necessary for the lithium-ion battery to function at high temperature. The solid electrolyte interface (SEI) of the ordinary lithium-ion battery, however, is very likely to disintegrate at high temperature. This may cause the swell of the battery and the degradation of the performance, and may also shorten the lifetime of the battery.