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Potassium‐ion batteries (KIBs) have recently attracted considerable attention owing to their resource abundance, low cost and environmental friendliness. Graphite as a mature commercial anode material for lithium‐ion batteries, has been proved as a promising anode candidate for KIBs by reversible forming potassium‐graphite intercalation compounds. However, large volume expansion and sluggish K+ kinetics caused by the incompatibility between large radius of K+ and the small interlayer spacing of graphite, result in the poor cycle stability and rate performances, hindering its practical application. Extensive research efforts have focused on improving the potassium storage performance of graphite anodes. This review provides an overview of recent advances in addressing these challenges and optimizing the electrochemical performance of graphite anodes for KIBs. Various strategies to improve the electrochemical performance of graphite and graphitic carbon anodes, such as microcrystalline regulation, heteroatom doping, morphological adjustment, and coating modification, are discussed, while the critical issues and challenges associated with graphite anodes and the prospects for their advancement in KIBs are highlighted. The review offers valuable guidelines for rational structural design and promotes the commercial development of high‐performance graphite anode materials for KIBs. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries (SIBs) are regarded as a kind of promising candidate for large‐scale energy storage technology. The development of advanced carbon anodes with high Na‐storage capacity and initial Coulombic efficiency (ICE) from low cost, resources abundant precursors is critical for SIBs. Here, a carbon microcrystalline hybridization route to synthesize hard carbons with extensive pseudo‐graphitic regions from lignite coal with the assistance of sucrose is proposed. Employing the cross‐linked interaction between sucrose and lignite coal to generate carbon‐based hybrid microcrystalline states, the obtained hard carbons possess pseudo‐graphitic dominant phases with large interlayer spaces that facilitate Na ion's storage and transportation, as well as fewer surface defects that guarantee high ICE. The LCS‐73 with an optimum cross‐link demonstrates the highest Na‐storage capacity of 356 mAh g−1 and an ICE of 82.9%. The corresponding full‐cell delivers a high energy density of 240 Wh kg−1 (based on the mass of anode and cathode materials) and excellent rate capability of 106 mAh g−1 at 10 C in addition to outstanding cycle performance with 80% retention over 500 cycles at 2 C. The proposed work offers an efficient route to develop high‐performance, low‐cost carbon‐based anode materials with potential application for advanced SIBs. [ABSTRACT FROM AUTHOR]

A plate-like Bi/Bi 2 O 3 -C heterostructure with boosted potassium storage performances is designed through a MOF-derived structure-inheritance strategy, where the Bi and Bi 2 O 3 can form hetero-particles that are uniformly embedded within the MOF-derived carbon skeleton. [Display omitted] Bismuth-based materials are regarded as promising anode materials for potassium ion batteries (PIBs) due to their high theoretical capacity and low working potential. However, the large volume expansion and sluggish kinetics during cycling are major limitations to their practical application. Herein, a unique Bi/Bi 2 O 3 -C heterostructure was designed through a simple Bi-metal–organic framework (MOF) modulation-pyrolysis process. X-ray photoelectron spectroscopy, transmission electron microscopy, and X-ray diffraction revealed that the Bi and Bi 2 O 3 can form hetero-particles, which were uniformly embedded in a plate-like carbon skeleton, constructing a Bi/Bi 2 O 3 -C heterostructure. The carbon skeleton and the formation of numerous hetero-interfaces between Bi, Bi 2 O 3 , and carbon can effectively promote the interfacial charge transfer, shorten the K+ diffusion pathway, and alleviate the volume expansion of Bi/Bi 2 O 3 during potassiation. Consequently, the Bi/Bi 2 O 3 -C heterostructure exhibited a high reversible capacity of 426.0 mAh g−1 at 50 mA g−1, excellent cycle performance of 251.8 mAh g−1 after 350 cycles with a capacity retention of 76.6 %, and superior rate capability of 82.7 mAh g−1 at 1 A g−1, demonstrating its promising potential for the application of PIBs anode. [ABSTRACT FROM AUTHOR]

The global pandemic of COVID-19 poses significant challenge to the recycling of disposable polypropylene (PP)-based waste masks. Herein, a simple but effective sulfonation route has been proposed to transform PP-based waste masks into value-added hard carbon (CM) anode materials for advanced sodium-ion batteries. The sulfonation treatment improves the thermal stability of the PP molecule, preventing their complete decomposition and the release of massive gas molecules during the carbonization process. Meanwhile, the oxygen functional groups introduced during sulfonation effectively facilitates the cross-linking between the PP chains, hindering the rearrangement of carbon microcrystalline structures and enhancing its structural disorder. As a result, the prepared hard carbon anode (CM-180) with a high disorder degree and minimal surface defects realizes a high sodium storage capacity of 327.4 mAh g−1 with excellent cycle and rate capability. In addition, when coupled with O 3 –NaNi 1/3 Fe 1/3 Mn 1/3 O 2 cathode, the fabricated sodium-ion full cell delivers a high energy density of 238 Wh kg−1 and achieves an outstanding rate capability with a retained capacity of 75 mAh g−1 even at an ultrahigh current rate of 50 C. This work offers a novel insight into transforming the waste masks to value-added hard carbons with promising prospects for sodium-ion batteries. [Display omitted] • Masks-derived hard carbons are prepared via sulfonation-carbonization treatment. • The obtained CM-180 anode delivers a high Na-storage capacity of 327.4 mAh g−1. • The sodium-ion full cells with CM-180 anode realize exceptional rate capability. [ABSTRACT FROM AUTHOR]