Study Of Tap Density And Primary Particle Of Ni-rich Ternary Material In Lithium Ion Battery

Technological innovation which relys on the innovation of energy patterns is the trend of the current era. As a typical representative of the new energy, lithium-ion battery plays an irreplaceable role on the industrial innovation of information society. The Ni-rich Li NixCoyMn1-x-yO2 oxide material which is considered to be a positive electrode in lithium ion battery material has great prospect and is of great research value.After worldwide research and development in recent years, the Ni-rich Li NixCoyMn1-x-yO2 oxide material has achieved great progress in practical applications, but still faces several critical challenges such as the unsatisfactory tap density and poor understanding about internal changes during the process of precursor preparation. These existing issues impede the Ni-rich Li NixCoyMn1-x-yO2 oxide material from achieving wider range of applications and also hinder people’s in-depth understanding about this material.Based on the background mentioned above, the main research contents of this paper are tap density of this material, the primary particles of this material and the impurities contained in this material.Through controlling these three major factors that affect the tap density of this material: the particle size distribution span, internal particle packing tightness and particle shape regularity, we succeeded in optimizing the tap density of both the precursor and sintered material of the Ni-rich Li NixCoyMn1-x-yO2 oxide material. During the expriments, we study about how these three factors change during optimization by several testing methods such as tap density test, particle size distribution test, specific surface area test and scanning electron microscopy. Ultimately, the tap density of the Ni-rich Li NixCoyMn1-x-yO2 oxide material reaches values of > 2.10 g / cm3 for the precursor and > 2.77 g / cm3 for the sintered materials.Through changing the preparation conditions including the reaction time, p H value, temperature and ammonia/metal ion feeding ratio, we study about how the primary particles change when single preparation condition changes in this paper. Combined with scanning electron microscopy, tap density test and the specific surface area test, the particle size, morphology and packing tightness of primary particles are investigated when preparation condition changes. In the end, we find how different conditions will affect the primary particles of the Ni-rich Li NixCoyMn1-x-yO2 oxide material and the causes of these effects. Meanwhile, we proposed the descending order of different preparation conditions depending on the degree of influence on the primary particles as follows: p H value>reaction time> ammonia/total metal ion feeding ratio> reaction temperature.Through combining multiple characterization methods such as XRD, XPS, CV, etc, we make a study about the impurities which are easily brought in during the preparation of the Ni-rich Li NixCoyMn1-x-yO2 oxide material by co-precipitation methods, especially during the precursor preparation and the drying processes. Here we introduce the effects that the impurities have on the electrochemical performances and the composition of the impurities. Furthermore, we propose the generation incentives of impurities, which can be a reference for other researchers.