TU-TESL

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According to foreign media reports, Argonne National Laboratory researchers developed a new method to produce cobalt free lithium-ion positive electrode, avoiding some problems in other production methods of low cobalt positive electrode. Earlier this year, arumugam manthiram, of the University of Texas, said: Currently, lithium-ion production is based on layered limo2 positive electrodes (M =   Ni, Mn, Co; NMC), which contain different proportions of manganese, cobalt and nickel. The manganese content is rich, harmless to the environment, but the conductivity is poor; at the same time, the cobalt content is small, the toxicity is relatively large, and it will become metallic after charging. In all standards, nickel content is between cobalt and manganese. In order to make full use of the advantages of the three ions, at present, the industry uses lini1-y-zmnycozo2 (1-y-z) < 0 > 0.2). Therefore, there are enough reasons to reduce or completely eliminate cobalt content and increase nickel content. However, the high content of nickel in limo 2 cathode will lead to some serious problems. Such as capacity reduction, poor thermal stability and air reactivity. This is because: (I) a series of phase transformation causes internal pressure; (II) high reaction activity with the electrolyte surface, forming a thick solid electrolyte interface; (III) high surface reaction activity with the surrounding air, resulting in a large number of LiOH and lihco3 on the surface. According to the Argonne team, the most popular production method of low cobalt positive electrode is to develop nickel rich layered LiMO2 (M   =   Ni, Mn, Co; NMC) oxides such as LiNiO2, in which the content of manganese and cobalt is low, such as NMC-811. However, there are some problems in safety, cycle life and cost. Argonne's team suggested improvements to the typical cobalt free layered oxide lini0.5mn0.5o2.