Selective Potassium Deposition Enables Dendrite‐Resistant Anodes for Ultrastable Potassium‐Metal Batteries

Abstract

Instability at the solid electrolyte interface (SEI) and uncontrollable growth of potassium dendrites have been pressing issues for potassium-ion batteries. Herein, a self-supporting electrode composed of bismuth and nitrogen-doped reduced graphene oxide (Bi 80 /NrGO) is designed as an anode host for potassium-metal batteries. Following the molten potassium diffusion into Bi 80 /NrGO, the resulting K@Bi 80 /NrGO exhibits unique hollow pores that provide K + -diffusion channels and deposition space to buffer volume expansion, thus maintaining the electrode structure and SEI stability. The K@Bi 80 /NrGO also provides a controlled electric field that promotes uniform K + flux, abundant potassiophilic N sites, and Bi alloying active sites, collectively enabling precise nucleation and selective deposition of potassium to achieve dendrite-resistant anodes. With the K@Bi 80 /NrGO-based optimized electrodes, the assembled K@Bi 80 /NrGO symmetrical cells can sustain stable cycling over 3000 h at a current density of 0.2 mA cm −2 . Full cells with a Prussian blue cathode and K@Bi 80 /NrGO anode exhibit high stability (with no degradation for 1960 cycles at 1000 mA g −1 ) with 99% Coulombic efficiency. This work may lead to the design of anodes with the triple attributes of precise nucleation, smooth diffusion, and dendrite inhibition, ideal for developing stable potassium-metal anodes and beyond.

Solvent-Free Synthesis of Hollow Carbon Nanostructures for Efficient Sodium Storage

“…Limited by lithium resources, carbon electrodes for other advanced alkali metal-based batteries , are gaining more attention, such as sodium ion batteries. The hollow structure is very suitable for electrode materials in sodium-ion batteries since the hollow structure not only offers a short diffusion distance to facilitate mass transportation but also buffers the destructive volume expansion of electrode materials during insertion/extraction of Na + , providing great potential for high-performance electrodes with high-capacity retention under large current density and long cycles.…”

“…Limited by lithium resources, carbon electrodes for other advanced alkali metal-based batteries 24,25 are gaining more attention, such as sodium ion batteries. The hollow structure is very suitable for electrode materials in sodium-ion batteries The electrochemical impedance spectroscopy (EIS) in Figure S11 shows a rapid rising phase degree curve in the Bold phase and the large angle straight line in the Nyquist plot at low frequency, confirming the fast electron/ion conductivity within HCF.…”

FeSe2 Graphite Intercalation Compound as Anode Materials for Sodium Ion Batteries

“…In order to identify the interaction between sodium and FeSe 2 -GIC-BM, X-ray photoelectron spectroscopy (XPS) was used to analyze each elemental component and valence state. , The existence of Fe, Se, C, and O elements is found in Figure a. After sodium ion insertion, Na 1s peaks appeared at 1072 eV and were accompanied by strong Auger peaks at 497 eV, as shown in Figure d.…”

Green Ether Electrolytes for Sustainable High‐voltage Potassium Ion Batteries

“…[20] Moreover, the large radius of K + reduces the charge density, which is conducive to obtaining weak cationsolvent interactions. [10,21] Therefore, the following electrochemical investigation is mainly focused on potassium ion batteries. The critical targets in this work are to improve the high-voltage stability and regulate the potassium ion solvation shell of ether-based electrolytes.…”