Graphene Foam-Protected Phosphorus Anode for Battery Volume Expansion

The patent creates a composite structure where phosphorus particles are encapsulated within a three-dimensional graphene network. The graphene component provides excellent electronic conductivity (10^3-10^4 S/m) while the phosphorus core maintains high lithium storage capacity (2500 mAh/g). This composite architecture allows the conductive graphene matrix to compensate for the poor intrinsic conductivity of phosphorus, enabling both high capacity and good electrical performance to coexist.

The patent employs a three-dimensional graphene network as a flexible encapsulating structure that surrounds phosphorus particles. This graphene shell acts as a buffer that can elastically deform to accommodate the approximately 100% volume expansion of phosphorus during lithium insertion, while maintaining structural integrity. The flexible graphene framework prevents particle fragmentation and electrode delamination, allowing the high-capacity phosphorus material to undergo repeated expansion-contraction cycles without degradation.

The patent introduces a conductive graphene layer as an intermediary between the phosphorus particles and the electrolyte. This graphene interface serves multiple functions: it facilitates efficient electron transfer to improve first-cycle efficiency, prevents direct contact between phosphorus and electrolyte that would cause harmful side reactions, and maintains stable electrical contact during volume changes. The graphene mediator thus improves both the initial efficiency and long-term stability of the phosphorus-based anode.