Surface phosphation of 3D mesoporous NiCo 2 O 4 nanowire arrays as bifunctional anodes for lithium and sodium ion batteries.

A novel surface phosphate strategy was adopted to dramatically improve the charge transport, ion diffusion, electroactive sites, and cycle stability of mesoporous NiCo ₂ O ₄ nanowire arrays (NWAs), drastically boosting their electrochemical properties. Consequently, the as-prepared phosphated NiCo ₂ O ₄ NWA (P-NiCo ₂ O ₄ NWA) electrode achieved excellent energy storage performance as a bifunctional anode material for both lithium ion batteries (LIBs) and sodium ion batteries (SIBs). When evaluated as an anode for LIBs, this P-NiCo ₂ O ₄ NWA electrode showed a high reversible capacity up to 1156 mA h g ^-1 for 1500 cycles at 200 mA g ^-1 without appreciable capacity attenuation, while in SIBs, the electrode could also deliver an admirable initial capacity as high as 687 mA h g ^-1 and maintained 83.5% of this after 500 cycles at the same current density. Most important, when the current density increased from 100 to 1000 mA g ^-1 , the capacity retention was about 63% in LIBs and 54% in SIBs. This work may shed light on the engineering of efficient electrodes for multifunctional flexible energy storage device applications.
Competing Interests: There are no conflicts to declare.
(This journal is © The Royal Society of Chemistry.)