The lithiophobic-to-lithiophilic transition on the graphite towards ultrafast-charging and long-cycling lithium-ion batteries

The extensive use of electric vehicles has raised the requirement of fast-charging for lithium-ion batteries. However, conventional graphite anode suffers from lithium dendrites and unacceptable capacity fade during fast charging. The limited ion channels and lithiophobic nature hinder the application of graphite in fast charging. Besides, the formation and accumulation of dead lithium accelerate the capacity decay during long-term cycling at high current density. Here, lithiophilic hard carbon-riveted graphite (HCRG) anode is delicately designed and fabricated to overcome the influence of dead lithium and meet the requirement of fast charging. The riveted heterostructure plays a crucial role in the lithiophobic-to-lithiophilic transition of graphite surface and the lithiophilic surface of HCRG can attract more Li-ions and facilitate re-intercalation of Li-ions into graphite bulk in relaxation time at low potential rather than plating on the surface, which effectively decreases the polarization and increases the proportion of reversible lithium at high current density. As a result, it exhibits excellent rate performance with 98.2% capacity retention when rate increasesing from 1 C to 15 C and fastcharging performance with 90.1% energy retention after 4000 cycles at an ultrahigh rate of 10 C in LiFePO4/ HCRG full-cell. This strategy of constructing riveted heterostructure efficiently boosts the lithium intercalation reaction. It achieves fast-charging performance, highlighting the comprehensive understanding of interfacial kinetics and structure optimization for other fast-charging anodes.

Automated summary

The extensive use of electric vehicles has increased the demand for fast-charging lithium-ion batteries. However, conventional graphite anodes face challenges during fast charging. In this study, a lithiophilic hard carbon-riveted graphite (HCRG) anode is designed to overcome the issues caused by dead lithium and meet the requirements of fast charging. By constructing a riveted heterostructure, the anode exhibits excellent rate performance and fast-charging performance.