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The performances of Ni-rich NCA90 Li-ion batteries with varied graphite tortuosities were explored. Low-tortuosity electrodes exhibited enhanced graphite utilization, impacting Li-ion diffusion/insertion and higher concentration of LiC12 phase, however achieving low energy density.

We conducted a detailed evaluation of the electrochemical performance of artificial graphite (AG) and natural graphite (NG) from four leading global companies: AG-1, AG-2, AG-3, and NG-4 towards Ni-rich Li-ion batteries. We found that AG-2, an artificial graphite variant, demonstrated superior performance with exceptional capacity, rapid charging capabilities, and impressive capacity retention. AG-2 achieved a specific capacity of 338.97 mAh g−1, outperforming AG-1 (321.16 mAh g−1), AG-3 (314.43 mAh g−1), and NG-1 (328.08 mAh g−1). This superiority was further confirmed by high C-rate tests ranging from 2 C to 5 C. Notably, after 500 cycles, AG-2 maintained 91.18% of its initial capacity, significantly surpassing AG-1 (89.44%), AG-3 (78.78%), and NG-1 (84.16%). The study attributes AG-2’s exceptional performance to its refined properties such as smaller particle size, fewer graphite imperfections, and a higher 2H phase content. These characteristics lead to increased active material in the anode, enhancing battery capacity, and to less material degradation over time, ensuring consistent capacity retention. Overall, AG-2 stands out as a highly efficient and cost-effective option for lithium-ion battery applications, eclipsing other commercial graphite alternatives.

Although Ni-rich layered oxide cathode materials of Li-ion batteries can provide high energy density, their performance degradation over long cycling and safety hazard due to their intrinsic property issues limit their practical long-term applications. Herein, we introduce a concept based on Ni-rich NMC811 core@quasi-solid shell structure. The Li-rich quasi-solid shell material was prepared by infusing 2 M LiTFSI in [EMIM][TFSI] into a whole pore of Al2O3nanoparticles delivering a high ionic conductivity (2.8 × 10−4 S cm−1) at room temperature (25 °C). Then the shell material with a thickness of ca. 200 nm below a “Play Dough-like” state was coated on NMC811 using a green and scalable mechanofusion process. The 18650 cylindrical Li-ion battery cells using the core-shell cathode and the graphite anode at a pilot-plant manufacturing scale exhibit considerable high-rate capability compared to the pristine NMC811, especially at a high C-rate. The post-mortem analysis demonstrated that with the thick semi-solid shell there is no transition metal dissolution. Also, the battery cells retained a high discharge capacity after long-term cycling without any safety hazards. We believe that the semi-solid encapsulation in this work may be useful for next-generation high-energy Ni-rich Li-ion batteries.