3D Printed Sodium‐Ion Batteries via Ternary Anode Design Affording Hybrid Ion Storage Mechanism

Abstract Sodium‐ion batteries (SIB), as one of the most appealing grid‐scale energy storage devices, have to deal with the trade‐off between the capacity output and rate performance. Utilizing 3D‐printed (3DP) anode materials with hybrid sodium storage mechanism and elevated mass loading is promising yet poorly explored. Herein, the design of a prototype ternary composite is reported, MoS 2 @Bi/N‐doped carbon, as a sodium storage candidate to achieve high reversible capacity (604 mAh g −1 at 0.1 A g −1 with an initial output of 709 mAh g −1 ) and outstanding rate capability (169.6 mAh g −1 at 15 A g −1 ), outperforming the state‐of‐the‐art reports. This is realized by delicate structural and interfacial engineering of the composite anode, markedly synergizing the conversion‐typed MoS 2 , alloy‐typed Bi, and adsorption‐typed N‐doped carbon. Theoretical simulations and operando instrumental analysis elaborate the reasons of the boosted electrochemical performance. Encouragingly, a fully 3DP SIB affording an areal mass loading of up to 11.7 mg cm −2 is demonstrated, retaining a capacity of 114 mAh g −1 at 1.0 A g −1 . This work would facilitate the design of 3DP SIB devices with the employment of advanced electrodes harnessing hybrid ion storage features.