From confined active materials to nacre-like electrode: Synergistic effect enabled superior lithium ion storage for high performance lithium ion batteries

Magnetite (Fe 3 O 4 ), regarded as a potential anode material, is still bothered by the fast and efficient lithium ion storage for lithium ion batteries (LIBs). Till now, most work mainly focuses on the modification of the active materials, regardless of the electrode morphology. High capacity of modified active material can be obtained at the expense of high content of carbon materials or delicately designed structure. In this study, active material modification and electrode morphology are both focused, which enable the electrode obtain superior lithium ion storage with high loading content of active material. The aerogel, in which modified active material are confined by the in-plane holey rGO backbone, is fabricated to improve the performance at the active material scale. The in-plane confined structure enables high tolerance to the structure stability and in-planes holes guarantee the rapid lithium ion diffusion. More interestingly, nacre-like stacked electrode, in which rGO sheets with confined active materials are layer-by-layer stacked at an electrode scale, can be fabricated by appropriately reduced rGO sheets and fitted content. The protrusions of the rGO sheets link the layers and act as micro spring to buffer the stress and strain, semiquantitively evidenced by calculation. The inter-space offers lithium ion transfer ways with the combination of the pores on the surface of electrode. Therefore, even with the high loading content (81 %), the anode exhibits a superior capacity with the specific capacity of 946 mAh g −1 after 300th cycle at 3 A g −1 . This design, from active material modification to electrode morphology, provides a new horizon for high performance lithium batteries. • In-plane holey graphene with confined active materials is obtained with a high Fe 3 O 4 loading content (81 %). • Interestingly, nacre-like electrode, in which layer-by-layer stacked composites are bridged by its protrusion, is fabricated. • The high structural stability of the unique nacre-like electrode is evidenced by calculation. • The nacre-like anode exhibits superior lithium ion storage (946 mAh g −1 after 300th cycle at 3 A g −1 ).