Heterostructured multi-yolk-shell SnO2/Mn2SnO4@C nanoboxes for stable and highly efficient Li/Na storage

Rationally designed transition metal oxides-based anode materials with superior electrochemical performance are still a challenge for Li and Na ion batteries (LIBs/NIBs). Herein, we have engineered novel multi-yolk-shell nanoboxes (denoted as SnO2/Mn2SnO4@C), which comprise heterostructured SnO2/Mn2SnO4 nanoparticles as yolk and phenolic resin-derived carbon as shell. The SnO2/Mn2SnO4 heterostructure can effectively hinder the coarsening of Sn and strengthen the reversibility of conversion and alloying process. Ascribing to lattice distortion and redistribution of the charge at SnO2/Mn2SnO4 heterostructure boundaries, Li+ and Na+ can rapidly migrate to anode, which accelerate the reaction kinetics. In addition, the hollow structure and phenolic resin-derived carbon shell of the SnO2/Mn2SnO4@C nanoboxes can alleviate disintegration and agglomeration of active composites. Owing to above advantages, the SnO2/Mn2SnO4@C nanoboxes as anode materials display a decent capacity of 1293 mA h g+1 after 100 cycles at 0.2 A g+1 and a splendid cycling stability at 2 A g+1 over 549 cycles for LIBs. For NIBs, a large reversible capacity of 203 mA h g+1 after 100 cycles at 0.2 A g+1 is delivered. Besides, electrochemical performances of Li (or Na) ion full cell are investigated by using the SnO2/ Mn2SnO4@C nanoboxes as the anode and LiFePO4 (or Na3V2(PO4)3) as the cathode.

Automated summary

A novel multi-yolk-shell nanoboxes composed of SnO2/Mn2SnO4 nanoparticles as yolk and carbon shell were designed for high-performance anode materials in Li and Na ion batteries. The heterostructure of SnO2/Mn2SnO4 effectively enhanced reversibility and reaction kinetics, leading to decent capacity and cycling stability. The hollow structure and carbon shell of the nanoboxes mitigated decomposition and agglomeration of active composites, showcasing promising potential in full cell applications.