Influence of sintering temperatures on microstructure and electrochemical performances of LiNi0.93Co0.04Al0.03O2 cathode for high energy lithium ion batteries

Abstract

In this study, we present a method for synthesizing Ni-rich LiNi0.93Co0.04Al0.03O2 (NCA) with a high-energy cathode material by the solid-phase method. The sintering temperature plays a very important role in the electrochemical performance of the LiNi0.93Co0.04Al0.03O2 since it affects the crystallinity and structural stability. Therefore, various sintering temperatures (660 °C/690 °C/720 °C/750 °C/780 °C/810 °C) are studied to get optimum electrochemical performances. The electrochemical performance of LiNi0.93Co0.04Al0.03O2 sintered at 720 °C shows the highest discharge capacity of 217.48 mAh g−1 with excellent Coulombic efficiency of 87.84% at 0.1 C. Moreover, the LiNi0.93Co0.04Al0.03O2 sintered at 720 °C exhibits excellent rate-capability (181.1 mAh g−1 at 2.0 C) as well as superior cycle stability (95.4% after 80 cycles at 0.5 C). This is because optimized sintering temperature leads to good structural stability with low cation disorder and residual lithium content.

Comparison Study of a Thermal-Driven Microstructure in a High-Ni Cathode for Lithium-Ion Batteries: Critical Calcination Temperature for Polycrystalline and Single-Crystalline Design

“…For the electrode that used N884-750, the charge-transfer resistance was significantly higher than that of the N884-800 electrode, most likely due to the low calcination temperature at 750 °C, which leads to degraded surface activity (Figure 3c). 28 The Coulombic efficiency showed similar trends with capacity retention (Figure S9). The electrode with N884-800 and SC N884-860, which showed excellent capacity retention, maintained an ∼99.9% Coulombic efficiency over 100 cycles.…”

“…It should be noted that there was a difference in the initial reversible discharge capacities of the electrodes depending on the synthetic conditions. For the electrode that used N884-750, the charge-transfer resistance was significantly higher than that of the N884-800 electrode, most likely due to the low calcination temperature at 750 °C, which leads to degraded surface activity (Figure c) . The Coulombic efficiency showed similar trends with capacity retention (Figure S9).…”

“…Among them, tailoring the microstructure has become a potential solution to improve cycle stability. Pore distribution and grain boundary structure in secondary particles help the accommodation of strain energy during cycling, significantly improving structural durability. ,, Since the microstructure of ceramics is easily controlled through variations in the type of dopant , or changes in synthesis temperature, , this strategy holds great potential for achieving long-term cycle retention of high-Ni cathodes.…”

Review—Advancements in Synthesis Methods for Nickel-Rich NCA Cathode Materials: Optimizing Synthesis Conditions and Their Impact on Electrochemical Performances for Next-Generation Lithium Batteries

“…The optimal calcination temperature range is critical to the electrochemical performance, resulting in strong structural stability, high cation ordering, high Li + diffusivity, and residual lithium concentration. 62 The influence of sintering is clearly investigated in the research paper of Hye-Jin Park et al 63 The study was performed at 660 °C/690 °C/720 °C/750 °C/780 °C/810 °C, and it concluded that the appropriate sintering temperature was 720 °C. The NCA synthesized at this temperature performs better.…”

“…This is since adjusting the sintering temperature results in good structural stability with low cation disorder and residual lithium content. Figure 2 63 pH effect.-In the case of co-precipitation and sol-gel methods, controlling the pH value of the reaction can be a key parameter for having an NCA cathode material with the desired characteristics in terms of size, shape, and tap density. Chunliu XU et al 64 investigate the NCA produced using a continuous hydroxide coprecipitation approach under different pH values (pH = 10.7, 10.9, and 11.1) with a fixed ammonia concentration.…”