Viable phosphomolybdic acid@polypyrrole via in-situ polymerization for high-performance lithium-ion storage

In the global pursuit of advanced energy materials, achieving enhanced performance while maintaining cost-effectiveness remains a critical challenge.

Herein, an economical composite of polypyrrole (PPy) coated phosphomolybdic acid (PMo₁₂) is fabricated through in-situ polymerization using readily available raw materials and low-energy synthesis processes. The resulting well-defined nanosphere PMo₁₂@PPy successfully preserves the structural integrity of both Keggin-type PMo₁₂ and conductive PPy matrix while demonstrating multiple enhanced properties.

When employed as an anode active material for lithium-ion batteries (LIBs), the PMo₁₂@PPy electrode delivers a high specific capacity and excellent long-term cycling stability. It maintains a capacity of 775 mA h g^-1 at 0.1 A g^-1 after 150 cycles, and retains 198 mA h g^-1 at 5 A g^-1 after 1200 cycles. The reconstruction of PMo₁₂@PPy into fine nanoparticles during cycling, coupled with the synergistic contribution from the multi-electron redox of PMo₁₂ and reversible pyridinic-N/pyrrolic-N conversion in PPy, markedly enhances its lithium storage capability. The practical viability of PMo₁₂@PPy is validated in full cells, which deliver impressive long-term cycling durability and can effectively power LED devices. Featuring both cost efficiency and excellent lithium storage capability, the PMo₁₂@PPy composite emerges as a highly competitive electrode material for advanced electrochemical energy storage.