A 3D Porous MgFe 2 O 4 Integrative Electrode as a Binder‐Free Anode with High Rate Capability and Long Cycle Lifetime

A superior 3D architecture Ni foam/MgFe 2 O 4 integrative electrode was firstly designed and synthesized via a simple hydrothermal method and subsequent calcination as a binder‐free anode for lithium‐ion batteries (LIBs). MgFe 2 O 4 nanoparticles with diameter of about 60 nm interconnect with each other to form porous nanosheets and anchor on the Ni foam (N‐MFO). The 3D architectural design with superior conductivity and a strong skeleton structure not only provides fast kinetics, reduces the polarization and enhances the rate performance, but also buffers volume expansion and improves the cycle stability during the discharge/charge process. In addition, the interfacial lithium storage of the N‐MFO electrode promotes high lithium‐storage capacity, superior cycle stability and impressive rate capability. Even cycling at a current density of 5 A g −1 for 1000 cycles, the capacity remains stable at about 780 mAh g −1 .