Recent Progress and Perspectives on Alloying Anodes for Potassium‐Ion Batteries

Abstract

Potassium‐ion batteries (PIBs) have been regarded as one of promising alternatives to lithium‐ion batteries (LIBs) due to the wide distribution, low‐cost potassium resources and high working voltage. Anode materials play a vital role in the future development of PIBs. Among the various anode materials, alloying anodes such as tin, antimony, phosphorus, bismuth and silicon show promising future and attracted wide attention owning to their wide distributed resources, favorable working voltage, and theoretically high capacities. However, the severe volume expansion during potassiation/depotassiation leads to pulverization and exfoliation from the current collector, resulting in capacity decay of PIBs. Efficient approaches, such as micro‐/nanostructures designing, carbon coating, and optimizing the interface between electrode and electrolyte have been utilized to solve these issues. In the present review, the research progress on alloying anode materials in PIBs is summarized. Considering the synthesis strategies, battery performance, battery working mechanisms, and structure‐performance relationships of these materials, the challenges and future development directions of alloying anode materials are suggested. Herein, we will provide an outlook for the development of high‐performance alloy‐based anode materials for PIBs and also indicate the future direction of electrode materials in PIBs.

Unveiling the Nature of Ultrastable Potassium Storage in Bi0.48Sb1.52Se3 Composite

“…In addition, introducing a buffer layer such as carbon-coating is another strategy, which not only provides a good conductivity but also buffers the volume expansion and mechanical stress effectively. Moreover, multiple-step alloying to form intermetallics is also an effective strategy, and using the synergistic effect of each element as flexible buffer base can improve the cycle stability significantly. ,− Based on these, a variety of multicomponent metal sulfides have been explored for PIBs. For example, the reported Bi 1.11 Sb 0.89 S 3 nanotubes achieved a promising long cycling stability .…”

FeSb2 Nanoparticles Embedded in 3D Porous Carbon Framework: An Robust Anode Material for Potassium Storage with Long Activation Process

“…Sb alloyed with Li and K will undergo three-electron transfer reactions to generate Li 3 Sb and K 3 Sb compounds, respectively, indicating that Sb exhibits the same theoretical capacity of 660 mAh g −1 for Li and K storage. [6] However, although the amount of K + and Li + accepted by an Sb atom is the same, owing to the larger intrinsic radius of K + , a huge volume change will occur during the potassiation/depotassiation process, which will certainly lead to the fragmentation and pulverization of Sb particles and eventually bring about an unstoppable decline in capacity. [7] In order to surmount the challenge of the dramatic volume variation of the Sb anode, an effective strategy is to reduce the size of Sb particles, because doing so can reduce the absolute volume change of an Sb entity and shorten the diffusion distance of K + .…”

Bimetallic-based composites for potassium-ion storage: challenges and perspectives

“…The challenges faced by alloy anodes were mainly attributed to the aggregation of the material and the crushing of the active material (separation from the collector) owing to volume expansion. 145,146 Metal Sb was usually chosen as one of the elements for alloy materials because of its ability to provide high capacity, while another metallic element buffered the volume expansion of the alloy during cycling. 147 However, the problem of aggregation and crushing of alloy materials was still unavoidable.…”

“…The challenges faced by alloy anodes were mainly attributed to the aggregation of the material and the crushing of the active material (separation from the collector) owing to volume expansion. 145,146…”