Nacre-Inspired Structure Enables Ultrahigh 'Strong-Tough' Design of Phosphorus Anode

Red phosphorus anode, attributed to its high specific capacity of 2596 mAh g^-1, is expected to improve the energy density of Na-ion batteries. However, the P anode currently is unsatisfactory for practical usage due to the large volume expansion beyond 300 %, which brings out uncontrolled brittle failure. To address this challenge, we here design a nacre-like phosphorus anode by resilient graphene oxide staggered together. The staggered structure simultaneously offers mechanical strength and interwoven toughness. Finite element modeling reveals that the sodiation stress from P nanoparticles will be transferred into interlayer pillars as the elastic medium to release sodiation stress. The prepared anode achieves an ultrahigh areal capacity of 13 mAh cm^-2 at a mass loading of 5.8 mg cm^-2. Notably, the volume change of the anode is limited to approximately 8.1 % at full sodiation, significantly lower than that of the traditional phosphorus electrodes.