Advanced Carbon‐Based Anodes for Potassium‐Ion Batteries

Abstract

The ever‐increasing demand for large‐scale energy storage systems requires novel battery technologies with low‐cost and sustainable properties. Due to earth‐abundance and cost effectiveness, the development of rechargeable potassium ion batteries (PIBs) has recently attracted much attention. Since carbon‐based materials are abundant, inexpensive, nontoxic, and safe, extensive feasibility investigations have suggested that they can become promising anode materials for PIBs. This review not only attempts to provide better understanding of the potassium storage mechanism, but also summarizes the availability of new carbon‐based materials and their electrochemical performance covering graphite, graphene, and hard carbon materials plus carbon‐based composites. Finally, the critical issues, challenges, and perspectives are discussed to demonstrate the developmental direction of PIBs.

Porous Carbons: Structure‐Oriented Design and Versatile Applications

“…[ 110 ] However, K has a larger atomic radius (1.38 Å) than Li (0.68 Å) and Na (0.97 Å), which limits the K ion diffusion and reaction kinetics in electrode. [ 110a ] As one of the most investigated KIB anode materials, [ 111 ] various porous carbon materials have been used for K‐storage, like soft carbon, [ 112 ] hard carbon (e.g., biomass or waste‐derived porous carbon [ 113 ] ), graphitic carbon, [ 114 ] or a combination of them (e.g., hard–soft carbon composite [ 115 ] ).…”

“…By comparison, the adsorption of K + onto the surface defects/functional groups or nanovoids of carbon is a surface‐induced capacitive process, which can favor fast ion diffusion and sustain excellent structure stability, promoting high rate and long cycling performance. [ 111 ] The capacitive contribution may originate from the double‐layer capacitance/pseudocapacitance behavior mainly occurring on the active surface, which can be enhanced by the increment of SSA and doping of heteroatoms, [ 116 ] without any damage to the electrode. For example, N/O doped macro/meso/microporous hard carbon microspheres (SSA = 1030 m 2 g −1 ) exhibited a capacitance‐dominant K‐ion storage.…”

“…[ 114 ] The formation of SEI film on high‐SSA carbon could be improved by surface coating or optimizing electrolyte and binder systems. [ 110a,111 ]…”

Tailoring 2D Heteroatom‐Doped Carbon Nanosheets with Dominated Pseudocapacitive Behaviors Enabling Fast and High‐Performance Sodium Storage

“…Carbon materials have been attracting great interests due to their available resource, excellent conductivity, structural stability, and are widely applied in the electrochemical energy storage system (EES) including supercapacitors and rechargeable batteries 1. Among them, amorphous carbon is considered as a promising alternative to graphite for sodium ion batteries (SIBs) owing to its enlarged carbon interlayer distance, diverse configurations and porous structure 2.…”

Highly Dispersed ZnSe Nanoparticles Embedded in N‐Doped Porous Carbon Matrix as an Anode for Potassium Ion Batteries

“…Meanwhile, the corresponding storage potassium mechanisms are also unclear due to the large radius of potassium ion, which makes the process of insertion and extraction more difficult and complicated. Thus, it is urgent to construct the advanced anode with outstanding performance and to explore the energy storage mechanism …”