Although K is readily inserted into graphite, the volume expansion of graphite of up to 60% upon the formation of KC, together with its slow diffusion kinetics, prevent graphite from being used as an anode for potassium-ion batteries (PIBs). Soft carbon with low crystallinity and an incompact carbon structure can overcome these shortcomings of graphite. Here, ultra-thin two-dimensional (2D) wrinkled soft carbon sheets (USCs) are demonstrated to have high specific capacity, excellent rate capability, and outstanding reversibility. The wrinkles themselves prevent the dense stacking of micron-sized sheets and provide sufficient space to accommodate the volume change of USCs during the insertion/extraction of K. The ultra-thin property reduces strain during the formation of K-C compounds, and further maintains structural stability. The wrinkles and heteroatoms also introduce abundant edge defects that can provide more active sites and shorten the K migration distance, improving reaction kinetics. The optimized USC electrode exhibits a reversible capacity of 151 mAh g even at 6400 mA g, and excellent cyclic stability up to 2500 cycles at 1000 mA g. Such comprehensive electrochemical performance will accelerate the adoption of PIBs in electrical energy applications.
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http://dx.doi.org/10.3390/molecules27092973 | DOI Listing |
Adv Mater
January 2025
School of Physics and Electronics, Hunan University, Changsha, 410082, P. R. China.
Single-electron transfer, low alkali metal contents, and large-molecular masses limit the capacity of cathodes. This study uses a cost-effective and light-molecular-mass orthosilicate material, KFeSiO, with a high initial potassium content, as a cathode for potassium-ion batteries to enable the transfer of more than one electron. Despite the limited valence change of Fe ions during cycling, KFeSiO can undergo multiple electron transfers via successive oxygen anionic redox reactions to generate a high reversible capacity.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Helmholtz Institute Ulm (HIU), Helmholtzstraße 11, 89081 Ulm, Germany.
Potassium-ion batteries (KIBs) have attracted significant attention in recent years as a result of the urgent necessity to develop sustainable, low-cost batteries based on non-critical raw materials that are competitive with market-available lithium-ion batteries. KIBs are excellent candidates, as they offer the possibility of providing high power and energy densities due to their faster K diffusion and very close reduction potential compared with Li/Li. However, research on KIBs is still in its infancy, and hence, more investigation is required both at the materials level and at the device level.
View Article and Find Full Text PDFNanotechnology
January 2025
Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
In the post-lithium-ion battery era, potassium-ion batteries (PIBs) have been considered as a promising candidate because of their electrochemical and economic characteristics. However, as an emerging electrochemical storage technology, it is urgent to develop capable anode materials that can be produced at low cost and on a large scale to promote its practical application. Biomass-derived carbon materials as anodes of PIBs exhibit strong competitiveness by their merits of low weight, high stability, non-toxicity, and wide availability.
View Article and Find Full Text PDFSmall
January 2025
Department of Material Science Engineering, Gachon University, Seongnamdaero 1342, Seongnam, 13120, Republic of Korea.
Herein, NaCl-templated mesoporous hard carbons (NMCs) have been designed and engineered with tunable surface properties as anode materials for potassium-ion batteries (KIBs) and hybrid capacitors (KICs). By utilizing "water-in-oil" emulsions, the size of NaCl templates is precisely modified, leading to smaller particles that enable the formation of primary carbon structures with reduced particle size and secondary structures with 3D interconnected mesoporosity. These features significantly enhance electrode density, reduce particle-to-particle resistance, and improve electrolyte wettability.
View Article and Find Full Text PDFChemSusChem
January 2025
Jilin University, School of Materials Science and Engineering, Renmin street 5988, School of Materials Science and Engineering, Jilin University, 130022, Changchun, CHINA.
Metal selenides hold promise as feasible anode materials for potassium-ion batteries (PIBs), but still face problems such as poor potassium storage kinetics and dramatic volume expansion. Coupling heterostructure engineering with structural design could be an effective strategy for rapid and stable K+ storage. Herein, CoSe/MoSe2 heterojunction encapsulated in nitrogen-doped carbon polyhedron and further interconnected by three-dimensional nitrogen-doped carbon nanofibers (CoMoSe@NCP/NCFs) is ingeniously constructed.
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