Rational design of NiO/NiSe@C heterostructure as high-performance anode for Li-ion battery.

Biphasic or multiphase heterostructures have promising futures in advanced electrode materials for energy-related applications because of their desirable synergistic effects. Here we prepared a rational NiO/NiSe@C heterostructure microsphere through carbonization, selenization, and oxidation using Ni-MOF as a precursor. Electrochemical studies were conducted to examine the Li storage characteristics, and density functional theory (DFT) was utilized to comprehend the underlying mechanism. When employed as the anode for LIBs, the NiO/NiSe@C showed a high specific capacity and long-term cyclic stability, with a specific capacity of 992 mAh g for 600 cycles at a current density of 0.2 A g. The NiO/NiSe@C exhibits a significantly enhanced lithium-ion diffusion coefficient ( [Formula: see text] ) value. The DFT results show that an electron-rich area forms at the NiO/NiSe heterointerface, where the metalloid selenium transfers electrons to the oxygen atoms. The lithiation reactions were improved dramatically by redistributing interfacial charges, which can trigger a built-in electric field that dramatically promotes the capacitance contribution of electrode materials, enhances the lithium storage capacity, and accelerates the ion/electron transmission. The rational synthesis of NiO/NiSe@C heterostructure can provide an idea for designing novel heterostructure anode materials.