Improving Fast Charging-Discharging Performances of Ni-Rich LiNi0.8Co0.1Mn0.1O2 Cathode Material by Electronic Conductor LaNiO3 Crystallites

Enhancing cyclic and in-air stability of Ni-Rich cathodes through perovskite oxide surface coating

Ni-rich layered oxides, such as LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811), are promising cathode materials for high-energy lithium-ion batteries. However, the relatively high reactivity of Ni in NCM811 cathodes results in severe capacity fading originating from the undesired side reactions that occur at the cathode-electrolyte interface during prolonged cycling. Therefore, the trade-off between high capacity and long cycle life can obstruct the commercialization process of Ni-rich cathodes in modern lithium-ion batteries (LIBs). In addition, high sensitivity toward air upon storage greatly limits the commercial application. Herein, a facile surface modification strategy is introduced to enhance the cycling and in-air storage stability of NCM811. The NCM811 with a uniform SrTiO₃ (STO) nano-coating layer exhibited outstanding electrochemical performances that could deliver a high discharge capacity of 173.5 mAh⋅g^-1 after 200 cycles under 1C with a capacity retention of 90%. In contrast, the uncoated NCM811 only provided 65% capacity retention of 130.8 mAh⋅g^-1 under the same conditions. Structural evolution analysis suggested that the STO coating acted as a buffer layer to suppress the dissolution of transition metal ions caused by the HF attack from the electrolyte and promote the lithium diffusion during the charge-discharge process. In addition, the constructed STO layer prevented the exposure of NCM811 to H₂O and CO₂ and thus effectively improved the in-air storage stability. This work offers an effective way to enhance the performance stability of Ni-rich oxides for high-performance cathodes of lithium-ion batteries.

A Review on Electrode Materials of Fast-Charging Lithium-Ion batteries

In recent years, the driving range of electric vehicles (EVs) has been dramatically improved. But the large-scale adoption of EVs still is hindered by long charging time. The high-energy LIBs are unable to be safely fast-charged due to their electrode materials with unsatisfactory rate performance. Thus it is necessary to summarize the properties of cathode and anode materials of fast-charging LIBs. In this review, we summarize the background, the fundamentals, electrode materials and future development of fast-charging LIBs. First, we introduce the research background and the physicochemical basics for fast-charging LIBs. Second, typical cathode materials of LIBs and the method to enhancing their fast-charging properties are discussed. Third, the anode materials of LIBs and the strategies for improving their fast-charging performance are analyzed. Finally, the future development of the cathode materials in fast-charging LIBs is prospected.

Improved Cycling Performance and High Rate Capacity of LiNi0.8Co0.1Mn0.1O2 Cathode Achieved by Al(PO3)3 Modification via Dry Coating Ball Milling

LiNi0.8Co0.1Mn0.1O2 (NCM811) has attracted extensive attention as a promising cathode of lithium-ion batteries (LIBs) in next-generation electric vehicles, as the NCM811 sample possesses a high energy density and a price advantage. In this work, NCM811 was modified with an Al(PO3)3 precursor using the dry ball milling method followed by heat treatment to enable commercial development both at room temperature and a higher temperature. Compared with the unmodified NCM811 sample with the capacity retention of 68.70%, after Al(PO3)3 modification, the NCM811 sample heated to 500 °C exhibited a super capacity retention ratio of 93.88% after 200 charging–discharging cycles with the initial discharge capacity of 178.1 mAh g−1 at 1 C. Additionally, after Al(PO3)3 modification, the NCM811 sample heated to 500 °C showed much improved rate performance compared to bare NCM811 at the current density of 5 C. The enhanced electrochemical performance after cycling was due to the decreased charge transfer resistance and increased Li+ transmission, which were confirmed via electrochemical impedance spectra (EIS). The NCM electrodes showed improved structural stability as layered structures after Al(PO3)3 modification, consistent with the improved cycling performance. This work revealed that LiNi0.8Co0.1Mn0.1O2 material with phosphide coating can be constructed using a simple ball milling method, which is feasible for obtaining high-performance electrode materials.