A layered Prussian blue analogue as fast-charging negative electrode material for lithium-ion batteries.

Abstract

The simultaneous achievement of fast-charging and high specific capacity remains a critical challenge for lithium-ion battery negative electrodes. Here we report a layered manganese-based Prussian blue analogue, synthesized through vacancy control and subsequent thermal transformation. As a conversion-type negative electrode, this material exhibits high-rate performance, delivering a specific capacity of 510 mAh g^-1 at a specific current of 8 A g^-1, and operates at a moderate average voltage of approximately 1.2 V vs. Li/Li⁺, which mitigates lithium plating risks. This high-rate capability stems from the analogue's specific linkage configurations, which facilitate a high content of active transition metal and strong Li⁺ adsorption at nitrogen sites. The high transition metal content enables a high reversible capacity, while strong Li⁺ adsorption promotes an efficient initial crystalline-to-amorphous transformation. This process induces dynamically reversible component migration during subsequent cycling, thereby enhancing conversion reaction kinetics. Our findings provide insights into the application of Prussian blue analogues as fast-charging negative electrode materials.