Electronic delocalization in polyoxometalates creates electron highways for ultrastable lithium storage

Area of Science:

• Materials Science
• Electrochemistry
• Inorganic Chemistry

Background:

• Polyoxometalates (POMs) offer low cost and multielectron redox chemistry for lithium-ion batteries (LIBs).
• Key limitations for POM anodes include poor electronic conductivity and limited lithium storage sites.
• Preyssler-type polyoxotungstates (P5W30) serve as a model to address these challenges.

Purpose of the Study:

• To investigate and enhance the electrochemical performance of POM-based LIB anodes.
• To elucidate the mechanism of improved electron transport via transition metal incorporation.
• To provide atomic-level insights for designing high-performance LIB anodes.

Main Methods:

• Incorporation of transition metals (Mn, Cu) into the P5W30 framework (TM-P5W30).
• Utilized in-situ XRD, in-situ EIS, ex-situ IR, ex-situ TEM, and theoretical calculations.
• Analyzed the formation of
• TM bridge
• architecture for electron and ion transfer.

Main Results:

• TM incorporation established
• electron highways
• within the P5W30-TM framework, enhancing conductivity.
• The
• TM bridge
• architecture facilitated efficient dual pathways for electron and ion transfer.
• Mn-P5W30 demonstrated a high capacity of 558 mAh g^-1 and over 1500 cycles of stability.

Conclusions:

• Transition metal incorporation effectively overcomes conductivity and storage limitations in POM anodes.
• The
• TM bridge
• architecture is crucial for reversible lithium insertion/extraction and cycling stability.
• This study provides a design strategy for advanced POM-based LIB anodes.