Unveiling Intrinsic Potassium Storage Behaviors of Hierarchical Nano Bi@N‐Doped Carbon Nanocages Framework via In Situ Characterizations

Abstract

Metallic bismuth has drawn attention as apromising alloying anode for advanced potassium ion batteries (PIBs). However,s erious volume expansion/electrode pulverization and sluggish kinetics always lead to its inferior cycling and rate properties for practical applications.T herefore,a dvanced Bibased anodes via structural/compositional optimization and sur-/interface design are needed. Herein, we develop abottomup avenue to fabricate nanoscale Bi encapsulated in a3 DNdoped carbon nanocages (Bi@N-CNCs) framework with av oid space by using an ovel Bi-based metal-organic framework as the precursor.W ith elaborate regulation in annealing temperatures,t he optimizedB i@N-CNCs electrode exhibits large reversible capacities and long-duration cyclic stability at high rates when evaluated as competitive anodes for PIBs. Insights into the intrinsic K +-storage processes of the Bi@N-CNCs anode are put forward from comprehensive in situ characterizations.

Organic–Inorganic Hybridization Engineering of Polyperylenediimide Cathodes for Efficient Potassium Storage

“…Unfortunately, the practical application of organic cathodes is still barricaded seriously by the lower utilization of redox active sites, sluggish kinetics and limited reversible capacities. It will facilitate the huge enhancement in the above aspects during (dis)charge processes via attenuating the energy barrier of each active site and optimizing structures/compositions meanwhile [12–14] . Generally, the large‐conjugated imide compounds consisting of active sites (C=C, C=O and C=N) display stable capacities and hold the possibility in enhancing utilization efficiency of more redox‐active sites, where the dissociation of C=C and C=N is particularly difficult to achieve owing to their high activation energies [15, 16] …”

From 0D to 3D: Dimensional Control of Bismuth for Potassium Storage with Superb Kinetics and Cycling Stability

“…While, the discharge/charge curves of the 0D-Bi, 1D-Bi, and 3D-Bi undergo huge polarization as the current density over 5 A g −1 (Figure S11, Supporting Information). To the best of our knowledge, the rate performance of the 2D-Bi is the best among all the reported Bi-based anode for KIBs, such as Bi@N-CNCs, [23] bismuthene, [33] Bi@NS-C, [34] Bi@C, [35] and bulk Bi [36] (Figure 2f). The cycle stability of different dimensional Bi is investigated under 10 A g −1 (Figure 2g).…”

“…[19][20][21] Based on the complete alloying reaction (Bi → K 3 Bi), it can deliver a high theoretical capacity of 385 mA h g −1 and a low reaction voltage of 0.34 V. However, huge volumetric change (506% for forming K 3 Bi) during charging/discharging and the derived electrode pulverization lead to poor cyclability and short cycle-life. [22] To address these issues, enormous efforts have been made to optimize the electrochemical properties of Bi-based anodes via appropriate structure design, such as hybridizing with carbonaceous matrix, [23] alloying with other metal, [24] and designing ultra-small nanoparticles. [25] Generally, the dimensionality of the reported Bi-based materials can be categorized into 0D, 1D, 2D, and 3D morphologies.…”

Alkali and alkaline-earth metal ion–solvent co-intercalation reactions in nonaqueous rechargeable batteries

“…30,31 In general, the conventional energy storage mechanism of rechargeable batteries is the insertion/extraction of naked ions into/from the host materials. [32][33][34] Before insertion into host materials, the ions must undergo a desolvation process, which inevitably slows the kinetics. Thus, eliminating the desolvation process would be an effective strategy to improve the reaction kinetics and thus achieve fast-rate charging batteries.…”