Nitrogen Doped Multi-channel Graphite for High Rate and High Capacity Li Ion Battery

Abstract

Nitrogen doped multi-channel graphite was successfully prepared by using nitrogen doping and KOH etching technologies. The three-electrode and EIS tests indicates that the etched graphite possesses lower electrochemical resistance than the pristine graphite. The coin cell tests demonstrate that N doped multichannel graphite possesses a specific capacity of 361 mAh/g and coulombic efficiencies of 91.4%. No dramatic irreversible capacity loss results from the increased specific surface area (from 1.60 to 2.08 m2/g), removing the need for a trade-off between irreversible capacity loss and surface area. Full polymer cells were fabricated and electrochemical capabilities were measured. In 3C fast charge protocol, the charging capacity can reach 51% within 10 min charge, and 100% within 30 min, demonstrating excellent fast charging characteristic. The fast charge cycle performance with 3C-rate charge and 1C-rate discharge from 4.35-3.0 V was conducted at RT temperature. The capacity retention is 94% after 600 cycles, which shows good cycle performance.