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.

Harnessing Plasma‐Assisted Doping Engineering to Stabilize Metallic Phase MoSe2for Fast and Durable Sodium‐Ion Storage

“…It is clear that P-1T-MoSe 2 NFs have much smaller polarization and higher diffusion coefficient during the sodiation/desodiation process, demonstrating extensively promoted Na + diffusion kinetics (Figure 4h,i). [50] As indicated in the above results, plasma-assisted P doping triggers the phase transition of MoSe 2 from 2H to 1T; however, conventional P doping shows no effect. To determine the 5a).…”

“…It is clear that P‐1T‐MoSe 2 NFs have much smaller polarization and higher diffusion coefficient during the sodiation/desodiation process, demonstrating extensively promoted Na + diffusion kinetics (Figure 4h,i). [ 50 ]…”

“…A b-value calculated based on Equation (S1) (Supporting Information) of 0.89 is obtained for P-1T-MoSe 2 NFs during both sodiation and desodiation processes (Figure 4d), demonstrating highly reaction reversibility with capacity contributed by both the diffusion-controlled and capacitance-controlled charges. [50,51] The capacitance charge contributions for P-1T-MoSe 2 NFs are calculated according to Equation (S2) (Supporting Information). It increases gradually as the scan rate increases and reaches a ratio of 82.6% at 2 mV s −1 (Figure 4e,f).…”

Selective Interface Synthesis of Cobalt Metaphosphate Nanosheet Arrays Motivated by Functionalized Carbon Cloths for Fast and Durable Na/K-Ion Storage

“…As is well known, inferior cyclability for most transition-metal oxides/sulfides/phosphides is the main factor that limits their practical applications. 9,30 In this work, the novel Co(PO 3 ) 2 NSs/CC anode shows excellent cycling stability even without any coating, carbon modification, and specific structure design, suggesting the great practical application value of the novel material. To investigate the structural stability of the Co(PO 3 ) 2 /CC anode, we tested the morphology of the Co(PO 3 ) 2 NSs/CC electrode after 100 cycles.…”

“…Up to now, various nanomaterials have been developed for battery systems. , Nevertheless, the commercial LIB anode, graphite, only could achieve an ultra-low capacity of 35 mA h g –1 and a limited capacity of 279 mA h g –1 in SIBs and PIBs, respectively. , Expanding the interlayer distancing could enhance the reversible capacity and improve the cyclability of graphite to some extent, but it is still far from practical applications . Although alloy-type (metallic and intermetallic materials) and conversion-type materials (metal phosphides/sulfides/oxides) exhibited high theoretical capacity, most reported materials suffered from large material pulverization and fast capacity fading caused by the huge volume expansion during repeated sodium/potassium ion intercalation/deintercalation process. − In addition, organic materials have demonstrated the capability of storing sodium/potassium ions, but the intrinsic low electronic conductivity and poor reaction reversibility still remain a big challenge that impedes further applications. , Various strategies, including delicate nanostructure design to facilitate reaction kinetics and coating or heteroatom doping to enhance electronic conductivity, have been developed to overcome these drawbacks. In spite of some encouraging success, the underlying limitations of the above-mentioned materials have not been fundamentally solved.…”