Lithium ion battery is a new type of high-energy battery developed in the 20th century. At the end of the 1960s, Broad head of Bell Labs and others first began to study the “electrochemical intercalation reaction”. In the early 1970s, Exxon Company designed a secondary battery with lithium metal as the negative electrode and TiS2 as the positive electrode. At the end of the 1970s, Bell Labs discovered that metal oxides can provide greater capacity and a higher voltage platform, and metal oxides began to be studied. In the 1980s, Good enough and others successively discovered the electrochemical value of LixCoO2, LixNiO2, and other layered materials (R-3m space group), and spinel lithium manganate (Fd-3m space group) as an electrode material The excellent performance. At the end of the 1980s, the Canadian Moli Energy Company introduced Li/MoS2 secondary batteries to the market, and the first commercial lithium secondary battery was born. In the 1990s, Bad hi and Good enough first conceived the use of olivine-type lithium iron phosphate as a cathode material for lithium-ion batteries for research. In the 1990s, Japan’s SONY company invented a lithium secondary battery with a carbon-based negative electrode and a lithium-containing compound as the positive electrode, and it was the first to realize industrial production. In 1993, Bellcore Telecommunications Corporation of the United States used the PVDF process to manufacture polymer lithium ion batteries (PLIB) for the first time. As the third-generation power batteries, lithium-ion batteries and polymer lithium batteries have higher energy density than valve-regulated sealed lead-acid batteries and Ni-MH batteries, while the mass specific energy of PLIB is as high as 200w.h.kg-1. Sufficient advantages, if it can solve the safety problem, it will be the most competitive power battery.
At present, oil and other traditional energy resources are increasingly scarce in the world, the rapid development of social urbanization, the impact of industrial and life pollution on the environment is becoming more and more prominent, people’s attention to environmental protection issues such as global warming and the deterioration of the ecological environment is increasing. , Such as solar energy, wind energy, tidal energy, etc., have been developed and utilized one after another. They are developing rapidly. For example, based on the current development speed, new energy sources will become the main energy source for American energy consumption by 2030. However, the supply of these new energy sources is unstable and discontinuous, so these energy sources need to be converted into electric energy and then output, which promotes the research on rechargeable batteries.
Looking for rechargeable batteries to replace traditional lead-acid batteries and nickel-cadmium batteries, and developing non-toxic and non-polluting electrode materials, electrolytes and battery separators, as well as batteries that do not pollute the environment, are currently the primary tasks of the battery industry. Traditional lead-acid batteries, nickel-cadmium batteries, and nickel-metal hydride batteries have short service life, low energy density, and environmental pollution, which greatly restrict their use. Compared with traditional secondary chemical batteries, lithium-ion batteries have the advantages of high specific energy, high working voltage, long cycle life, fast charging, etc., and have been widely used in portable electronic devices such as mobile phones, notebook computers, digital cameras, etc. on. In a situation where global energy and environmental problems are becoming increasingly severe, all parties are striving to advocate energy conservation, emission reduction, and low-carbon environmentally friendly life, and the use of “clean cars” will become an inevitable development trend. The power battery should be a high-capacity, high-power battery. Compared with other secondary batteries, the recyclable lithium-ion battery has many advantages. It is considered an ideal choice for power batteries. Therefore, there has been a worldwide upsurge in the research and development of lithium-ion batteries, and major breakthroughs have been made in lithium-ion battery material technology, production technology, and equipment technology. From the perspective of research hotspots in the past ten years, lithium The research of ion batteries in secondary batteries can be said to be unique.