Achieving High‐Performance Metal Phosphide Anode for Potassium Ion Batteries via Concentrated Electrolyte Chemistry

Abstract

Metal phosphides are regarded as promising anode candidates for high‐energy‐density potassium‐ion batteries (PIBs) due to their high theoretical capacity and relatively low operation voltage. The failure mechanism of the metal phosphides originates from the large volume variation during cycling, which leads to fast capacity degradation. Herein, concentrated electrolyte is used to achieve impressive cycling stability for K‐metal and K‐ion batteries over their more dilute counterparts, mainly benefiting from the anion‐derived robust and uniform solid–electrolyte interphase layer, which is helpful in maintaining the electrode integrity, avoiding excessive side reactions, and suppressing electrolyte decomposition. Further investigations also reveal the synergistic advantages of the superior chemical compatibility of concentrated electrolyte to potassium metal, as well as its remarkable electrochemical stability and enhanced safety compared to conventional dilute electrolytes. This work provides a feasible strategy to mitigate the degradation of metal phosphides to build high‐energy‐density PIBs.

Nitrogen and Fluorine Dual Doping of Soft Carbon Nanofibers as Advanced Anode for Potassium Ion Batteries

“…[8] However, PIBs are suffering from poor rate capability and short cycling lifespan due to the larger radius of K + (1.38 Å) than that of Li + (0.76 Å), [15,16] which causes the collapse of solid electrolyte interphase (SEI) and active materials, exacerbating side reactions and extensive volumetric change during potassium insertion/extraction. [17][18][19][20] Hence, it is significant to seek alternative PIBs anode materials with favorable structural stability.Recently, great efforts have been made in the development of high-performance PIBs anode materials, such as sulfides, [18,19,21] phosphides, [22] carbonaceous, [23] and metallic materials, [24,25] etc. Among them, carbon-based materials have become one of the most promising PIBs anode due to their high conductivity, low potential platform, and structural stability in charging/ discharging process.…”

“…Recently, great efforts have been made in the development of high-performance PIBs anode materials, such as sulfides, [18,19,21] phosphides, [22] carbonaceous, [23] and metallic materials, [24,25] etc. Among them, carbon-based materials have become one of the most promising PIBs anode due to their high conductivity, low potential platform, and structural stability in charging/ discharging process.…”

Metal–organic framework‐derived phosphide nanomaterials for electrochemical applications

“…A doable strategy is provided to allay the remission of MPs to develop high-energy-density PIBs. 232 The electrochemical exhibition of these electrodes has been investigated by electrochemical impedance spectroscopy, cyclic voltammetry, and polarization measurement. The primary outcomes show that the porous Ni-Cr-Fe electrode has relatively good and lasting stability and excellent catalytic activity for HER in seawater.…”

Interphases in the electrodes of potassium ion batteries

“…graphite [78]), conversion-type (e.g. metal oxides [79], chalcogenides [80], and phosphides [81]), and alloying-type (e.g. Bi [82] and Sb [83]).…”