Revisiting the Effect of Natural and Artificial Graphite on the Performance of Ni-rich Li-ion Batteries at Coin and Cylindrical Cells

Abstract

Abstract 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, outperforming AG-1 (321.16 mAh/g), AG-3 (314.43 mAh/g), and NG-1 (328.08 mAh/g). This superiority was further confirmed by high C-rate tests ranging from 2C to 5C. 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.