![]() ![]() Two synthesis methods have been compared and one of the two reveals that an excess of aluminium can harm the cycling performance of a battery. The results also reveal an enhancement in terms of specific capacity, capacity retention, rate capability as well as the polarisation behaviour. Notably, the significant effect of the coating is underlined by an improvement of the cycling performance at high temperature (45 ☌) and at high cut-off voltage (3.0–4.4 V vs. In this article, we present the preparation and the surface and structural modification of LiO 2 (NMC622) through a one-pot synthesis followed by the annealing process which successfully coats the material with LiAlO 2. 27 Hence, in the present study, we aim to develop a simple, scalable, cost-effective and one-pot LiAlO 2 coating by using only a continuous stirred-tank reactor (CSTR). With respect to the coating of LiAlO 2, the most common methods used are wet-chemical deposition, 24 sol–gel deposition, 25 atomic layer-deposition, 26 and dry powder coating. 22 They all act as a physical barrier between the electrolyte and the cathode material to suppress side reactions. Indeed, a plethora of compounds have been investigated as cathode treatments such as metal oxides ( e.g., ZrO 2, 10 ZnO, 11 TiO 2, 12 Al 2O 3, 12,13 SiO 2 14), metal fluorides ( e.g., LiF, 15 LiAlF 4, 16 AlF 3 17), metal phosphates ( e.g., AlPO 4, 18 FePO 4, 19 Li 3PO 4 20), carbon, 21 and polymers. Additionally, the coating layer can prevent phase transformation from layered to spinel/rock-salt phase during cycling. Surface modification via coating is an effective method to prevent several degradation processes including transition metal dissolution and side reactions between the cathode surface and the electrolyte. To address these pitfalls, different strategies have been developed such as elemental doping, 8 core–shell structure, 9 and surface coating. 7 This cation mixing leads to a higher activation energy barrier for Li + diffusion and causes mechanical stress in the secondary particle structure, which reduces the specific capacity of the battery. 6 Another reason can be attributed to Li +/Ni 2+ cation mixing which manifests as Ni 2+ ion occupying 3b Li sites in the Li slab because of their similar radii (0.076 nm for Li + and 0.069 nm for Ni 2+). Li +/Li, the oxidation of Ni +3 to Ni +4 is accompanied by a release of oxygen that causes the degradation of the electrolyte and the production of heat. It has been reported that when charging the battery to 4,3 V vs. One reason for that is its undesired interfacial side reactions with the electrolyte. However, Ni-rich NMC exhibits several limitations, which lead to decreased cell performance over time. 4 On the other hand, the high nickel content provides superior battery specifications through higher energy density and enhanced safety. 2 On the one hand, there is a drive to reduce the amount of cobalt in LIBs due to its high cost and unsustainable production. Among them, Ni-rich NMC offers lower cost than LCO and higher thermal stability than LNO. 3įor EV batteries, a wide range of cathode materials have been developed such as LiFePO 4 (LFP), LiCoO 2 (LCO), LiMn 2O 4 (LMO), LiNiO 2 (LNO) and LiO 2 (NMC). 1,2 Likewise, EVs are a green replacement to internal combustion engine vehicles, and their success is mostly due to their higher energy efficiency, low operating cost, and eco-friendliness compared to gasoline powered vehicles. The success of LIBs is mostly due to their high energy density, long cycling life and power characteristics. Introduction Lithium-ion batteries (LIB) have developed rapidly and are considered as the technology of choice in the market of batteries for electric vehicles (EV). EIS confirms that the LiAlO 2 coating layer prevents side reactions resulting in reduced cathode electrolyte interphase formation and charge-transfer resistance. ![]() Li +/Li), the coated samples indicate a significant improvement in cycling performance (specific capacity, capacity retention, and rate capability). By comparing electrochemical performances and thermal stabilities of the coated and uncoated NMC particles at high temperature (45 ☌) and at high cut-off voltage (3.0–4.4 V vs. 27Al MAS NMR coupled with structural characterisation of the materials confirms the presence of a coating layer of LiAlO 2 on the surface of the NMC particle with partial diffusion of Al 3+ from the surface coating to the NMC structure. The composition and morphology of the coated and uncoated cathode materials were characterised by MP-AES, XPS, SEM, and EDX. Two methods of surface coating were compared with the pristine sample. For the first time, a one-pot synthesis of LiAlO 2-coated LiNi 0.6Mn 0.2Co 0.2O 2 particles, using a continuous stirred-tank reactor, is reported. ![]()
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