Nitrogen-rich graphene aerogel with interconnected thousand-layer pancake structure as anode for high performance of lithium-ion batteries

Abstract

Nitrogen-rich graphene aerogel with interconnected thousand-layer pancake structure (NTLP) was designed and fabricated through hydrothermal template self-assembly method using polystyrene (PS) nanospheres as structural guiding templates and ethylenediamine (EDA) as a nitrogen resource for in-situ N-doping. NTLP exhibits significantly improved electrochemical performance of lithium-ion storage including a highly reversible capacity of 1147 ​mA ​h g−1 at 0.1 ​A ​g−1, and favorable rate capability of 258 ​mA ​h g−1 even at a large current density of 5 ​A ​g−1. Moreover, the reversible capacity is retained at 501 ​mA ​h g−1 after 1100 cycles at 1 ​A ​g−1. PS template effectively alleviates the aggregation of graphene membrane, meanwhile forms peculiar thousand-layered cake structure with high specific surface area and well-controlled pores. Precisely owing to the unique structure with three-dimensionally (3D) interconnected holey graphene network and the introduction of abundant N-doping (about 7 atom%) into the graphene walls, NTLP significantly enhances the electrochemical activity and effectively accelerates the diffusions of both lithium-ions and electrons. The high performance strongly indicates that NTLP possesses a promising perspective for lithium-ion batteries with excellent electronic conductivity, efficient transport pathways of electrons and ions as well as superior reversible lithium storage capacity.