Binary carbon-based additives in LiFePO₄ cathode with favorable lithium storage

Abstract

A pairwise coupling of 0D Super-P (SP), 1D carbon nanotubes (CNTs), and 2D graphene nanosheets (GNs) into binary carbon-based conductive additives was used here for the LiFePO4 cathode in lithium-ion batteries. For comparison, the LiFePO4 cathode with SP, CNT, or GN unitary conductive agent was also examined. Electrochemical test results suggest that the cathodes with binary conducting additives present greatly improved electrochemical performance than the traditional cathode system (only SP used). Especially, the LiFePO4 cathode containing 3% CNT component exhibits the highest specific capacity and the best cycling stability among all the cathodes with binary conducting additives, indicating that an appropriate amount of CNTs is critical in enhancing the conductivity and practical capacity output. However, an excess of CNTs leads to entangling with each other, hampering the uniform distribution of active materials and resulting in poor electrode performance. Furthermore, the combination of CNT and GN can effectively improve the capacity and cycling stability of the LiFePO4 cathodes due to the synergistic effect of 3D conductive networks constructed by the two.

A Comparative Review of Metal Oxide Surface Coatings on Three Families of Cathode Materials for Lithium Ion Batteries

“…On a positive note, the reduction of the LiFePO 4 particles to the nanosize provides short Li + -ion diffusion paths within the positive electrode [76][77][78]. Additionally, the conductivity of LiFePO 4 is improved through coating of the material with a conductive carbon between particles providing high diffusion kinetics and preventing particles agglomeration [74,[77][78][79][80][81].…”

Mesoporous Carbon as Conductive Additive to Improve the High‐Rate Charge/Discharge Capacity of Lithium‐Ion Batteries

“…To the best of our knowledge, this is the best high‐rate charge/discharge capacity of LiFePO 4 cathode among the reported results (Figure 4d). [ 48–54 ] In the control experiment, the capacity of BMC‐1400 after sand milling for 1.5 h at 5 C dramatically reduced to 82 mAh g −1 (Figure S6a, Supporting Information), much lower than that of BMC‐1400. Moreover, a severe attenuation of capacity can be seen during the cycle process (Figure S6b, Supporting Information).…”

Macromolecular Engineering of Polyquinone-Based Electrode Materials for High-Energy Supercapacitors

“…Furthermore, conjugated PQs integrate with highly active groups of quinones and Schiff-base imines and additional hydroxyl sites, which improve the redox behaviors . Finally, the incorporation of highly conductive graphene into PQ-4 effectively enables the fast electron transport and ion diffusion while reducing the internal resistances, substantially enhancing redox kinetics and electrochemical utilization throughout the whole electrode. , …”

“…64 Finally, the incorporation of highly conductive graphene into PQ-4 effectively enables the fast electron transport and ion diffusion while reducing the internal resistances, substantially enhancing redox kinetics and electrochemical utilization throughout the whole electrode. 53,65 4. CONCLUSIONS Four PQs with tailored substituent hydroxyl groups were synthesized by Schiff-base condensation between phthalaldehydes and anthraquinones.…”