Ni₂P immobilized on N,P-codoped porous carbon sheets for alkali metal ion batteries and storage mechanism

Hybridization of electroactive nanomaterials in a porous carbon matrix can effectively solve the concerns of low electronic conductivity, kinetic retardation and large-volume changes because of the synergy amongst functional constituents. Herein, a novel integrated composite architecture obtained through an efficient self-designed self-templating strategy is presented and is composed of appropriately sized Ni2P nanoparticles (20-50 nm) confined in N/P codoped porous carbon nanosheets (Ni2P subset of N/P-CNS) as an anode material for potassium-ion batteries (PIBs). The Ni2P subset of N/P-CNS electrode exhibits feasibility and excellent potassium storage performance, possessing high reversible capacity, excellent rate capability and high stability and is also a viable option for lithium and sodium ion batteries. The fast potassium-ion reaction kinetics and strong adsorption of K+ ions in Ni2P subset of N/P-CNS are validated by the theoretical calculation investigation, promoting the improved potassium storage. The solid solution mechanism is confirmed to react with alkali metal ions through a series of rational characterization technologies and analyses. It favors the structural stability of Ni2P subset of N/P-CNS during electrochemical reactions. The work gives us a new inspiration of designing advanced and prospective electrode materials.