Recent Advances in Heterostructured Anode Materials with Multiple Anions for Advanced Alkali-Ion Batteries

As rechargeable battery technology continues to advance, the development of advanced electrode materials is becoming increasingly crucial to meet the emerging demand for electrochemical energy storage devices with higher energy and power densities. However, progress in anode materials has been sluggish and graphite is still widely applied in commercial rechargeable batteries. Alloying and conversion reaction-based anode materials, including Si, Sn, metal oxides, and metal chalcogenides, have been widely investigated as they exhibit much higher theoretical capacities than carbonaceous materials. However, they exhibit several intrinsic limitations, such as large volume change, low electrical conductivity, and high voltage hysteresis. Recently, the construction of heterostructures for anode materials has received increasing attention as it is an effective strategy to greatly enhance the capacity and rate performance by forming built-in electric fields at the heterointerfaces, which can lower the activation energy for surface reactions. This review introduces the recent progress in the development of heterostructured anode materials with an emphasis on metal compounds with multiple anions and various interpretations of the origin of their superior electrochemical properties in rechargeable alkali-ions (Li⁺, Na⁺, and K⁺) batteries. The challenges and future outlook of advanced heterostructured anode materials research are discussed at the end of this review.