Engineering Heterostructure-Incorporated Metal Silicates Anchored on Carbon Nanotubes for Highly Durable Lithium Storage

Although transition metal silicates are recognized as high potential and attractive materials for next-generation lithium-ion batteries (LIBs) due to their efficient energy storage, earth-abundance without pollution, low cost, and easy preparation, however, the unstable electrochemical stability originating from the intrinsic mechanism involved in long-term cycling tests is always of concern and needs to be decoupled stepwise. Herein, a strategy is proposed to overcome the challenges through the construction of a heterostructure using a facile hydrothermal method in combination with carbon nanotubes (CNTs), the composite. By tailoring a capacitive contribution over diffusion toward total charge storage in the heterostructure, CNT-coated heterostructural copper–nickel silicates (CNT@NiCuSi) were employed as the anode to achieve a relatively high capacity (412 mAh g–1 at 0.2 A g–1) and prolonged life for durable LIBs (91% retention after 1000 cycles at 0.5 A g–1). The heterostructure generated by NiSi/CuSi could lower the polarization of the composite and elevate its cycle stability, rendering the metal silicate favorable for LIBs. As a consequence, the practical application is evaluated by assembling a full cell based on CNT@NiCuSi as the anode and LiNi0.8Co0.1Mn0.1O2 (NCM811) as the cathode yielding a reversible capacity of 429 mAh g–1, along with a decent capacity retention of 221 mAh g–1 at a current density of 0.5 A g–1 after 300 cycles. This strategy opens an avenue for constructing long-life metal silicate-based nanocomposites for LIBs.