7/20/2023 0 Comments Nmc cathode sinterizingIn this paper, we report the synthesis of LiNi 0.91Co 0.06Mn 0.03O 2 (denoted as NCM91) cathode materials at various sintering temperatures. It is reported that crystallinity, morphology and structural stability, influenced by the sintering temperatures, all play an important role in the electrochemical performances, especially for Ni-rich cathode 11. (iii) disintegration derived from mechanical which stress deteriorate the long term stability by consuming active lithium 11, 12. (ii) undesirable materials on the cathode surface from reaction with transition metal ions and electrolyte cause performance decay. There are three main reasons for performance degradation of Ni-rich cathode: (i) cation disorder decreases the capacity, closely related to phase transformation of layered structure to a spinel or rock-salt structure. Therefore, the future of NCM for high energy LIBs strongly depends on Ni-rich NCM materials. Li(Ni 1/3Co 1/3Mn 1/3)O 2 has been successfully commercialized as a battery cathode, researches on Ni-rich NCM (LiNi xCo yMn 1−x−yO 2, x > 0.5) have been spotlighted due to its superior capacity (>200 mAh/g, at 4.6 V vs. Among the various cathode candidates, layer structured Li(Ni,Co,Mn)O 2 (NCM) has been regarded as the most attractive alternative to LIBs owing to relatively modest volume change (LiCoO 2), high specific capacity (LiNiO 2) and good thermal stability (LiMn 2O 4) 7, 8, 9. The energy density of LIBs is mainly determined by the cathode since the commercial carbonaceous anode potential is ~0 V 6. Thus, LIBs are widely used in electric vehicles (EVs), hybrid electric vehicles (HEVs), golf carts, electric bicycles, portable devices and so on. In the case of ECs, various attempts have been made to improve the energy density however, it is difficult to realize the high energy density of the LIBs (~200 Wh/kg) which is the greatest advantage for energy storage application 5. LNO Li-ion battery NMC Ni-rich layered oxide calcination cathode heat-treatment.The importance of energy storage devices is rapidly increasing, and various energy storage devices such as lithium ion batteries (LIBs), sodium-ion battery, electrochemical capacitors (ECs) and hybrid supercapacitors are being studied 1, 2, 3, 4. The importance of a careful selection of the heat treatment (calcination) temperature for each individual cathode material was emphasized. Despite their well-ordered structure, the materials calcined at higher temperatures were characterized by a stronger sintering effect, adverse particle growth, and higher Ni 2+/Li + cation mixing, thus deteriorating their electrochemical properties. The NMC-900 calcined at 900 ☌ and the LNO-700 calcined at 700 ☌ showed the most favorable electrochemical performances. With increasing nickel content, the optimal calcination temperature shifts towards lower temperatures. It was determined that the optimal calcination temperature is dependent on the chemical composition of the cathode materials. The correlation of the calcination temperature, structural properties and electrochemical performance of the studied Ni-rich layered cathode materials was thoroughly investigated and discussed. The samples obtained at different calcination temperatures (750-950 ☌ for the NMC622 and 650-850 ☌ for the LNO cathode materials) were characterized using nitrogen physisorption, PXRD, SEM and DLS methods. Ni-rich layered oxides, i.e., LiNi 0.6Mn 0.2Co 0.2O 2 (NMC622) and LiNiO 2 (LNO), were prepared using the two-step calcination procedure.
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