Tunable Hollow Nanoreactors for In Situ Synthesis of GeP Electrodes towards High‐Performance Sodium Ion Batteries

Abstract

The practical application of germanium phosphide (GeP) in battery systems is seriously impeded referring to the sluggish reaction kinetics and severe volume change. Nanostructure design that elaborately resolves the above issues is highly desired but still remains a big challenge. Herein, unique hollow nanoreactors assembled with nitrogen‐doped carbon networks for in situ synthesis of the GeP electrodes are proposed for the first time. Such nanoreactors form a self‐supported conductive network, ensuring sufficient electrolyte infiltration and fast electron transport. They restrain crystal growth and accommodate the volume expansion of GeP simultaneously. Reaction kinetics and confinement effect are optimized through nanoreactor size regulation. The optimized GeP electrode has high reversible capacities and outstanding cyclability and rate performance for sodium storage, outperforming most previously reported phosphides.

Advances in metal phosphides for sodium‐ion batteries

“…Comparison of the electrochemical performance of advanced MPs (e.g., GeP 5 , 131 FeP 4 , 61 GeP 3 , 134 NiP 3 , 78 GeP, 155 Sn 4 P 3 , 156 CuP 2 , 94 MnP 4 , 157 FeP, 22 CoP, 125 SnP 3 , 158 SnP, 19 Zn 3 P 2 , 159 CoP 4 , 34 Ni 2 P, 85 MoP, 153 WP, 146 ZnP 2 , 149 Co 2 P, 160 Ni 5 P 4 , 89 CoP 3 , 26 Cu 3 P, 161 V 4 P 7 , 143 and Ni 12 P 5 88 )…”

“…Up to now, all kinds of GeP x have been successfully fabricated, the synthetic methods are still limited, and mainly is high energy ball milling methode 18,127,130–134 . In addition, the other methods have also been developed to a lesser extent, such as one‐step and template‐free approach, 135 oriented growth technique, 136 lithiation‐assisted chemical exfoliation technique, 24 and electrospinning approach coupled with phosphorization process 137 . Among the GeP x ‐based systems, the layered GeP 5 possesses the highest P content and shows higher metallic conductivity even than that of graphite 132,138 .…”

“…18,127,[130][131][132][133][134] In addition, the other methods have also been developed to a lesser extent, such as one-step and template-free approach, 135 oriented growth technique, 136 lithiation-assisted chemical exfoliation technique, 24 and electrospinning approach coupled with phosphorization process. 137 Among the GeP x -based systems, the layered GeP 5 possesses the highest P content and shows higher metallic conductivity even than that of graphite. 132,138 Using a method of high-energy milling, Li et al prepared a GeP 5 /C composite through a two-step high-energy ball milling method.…”

“…F I G U R E 2 0 Comparison of the electrochemical performance of advanced MPs (e.g., GeP 5 , 131 FeP 4 , 61 GeP 3 , 134 NiP 3 , 78 GeP, 155…”

Phosphide-Enhanced Hierarchical NiMoO4 Composite in Binder-Free Ni-Electrodes for High-Capacity Aqueous Rechargeable NiZn Batteries

“…In recent years, transition metal phosphides have attracted more attention in the energy storage field due to their good conductivity and thermal stability. At present, researchers focus on controlling the composition or morphology of transition metal phosphide themselves to improve energy density and cycle life. − Researchers also synthesize complex multiscale nanocomposites with enhanced conductivity by adjusting the degree of phosphorylation or active components. For example, Zeng et al reported a new high-energy-density electrode material P-NiCo 2 O 4– x with enriched oxygen vacancies and surface phosphate ions by using a simple phosphating process.…”