A novel strategy for encapsulating metal sulfide nanoparticles inside hollow carbon nanosphere-aggregated microspheres for efficient potassium ion storage

Abstract

Tremendous efforts are being made to develop advanced electrode materials for potassium-ion batteries (PIBs), which have the potential to replace the currently dominant power source, lithium-ion batteries. Herein, an innovative...

Rational Design and Engineering of 1D Heterostructured Porous Sn/CoSnx@C Nanotubes for Superior Lithium Storage

“…On the one hand, the positions of the anodic and cathodic peaks in the CV curves are different, which is due to different components resulting in diverse lithium insertion/desertion mechanisms. On the other hand, compared with the Sn/CoSn x @C anode, the CV curves of the contrast anodes cannot remain unchanged, indicating lower cycle stability; especially the small CV area indicates relatively low specific capacity due to the difference in ion transfer rate and volume expansion during the charging/discharging process, further suggesting the structural and component advantages for the Sn/CoSn x @C anode materials. , …”

“…On the other hand, compared with the Sn/CoSn x @C anode, the CV curves of the contrast anodes cannot remain unchanged, indicating lower cycle stability; especially the small CV area indicates relatively low specific capacity due to the difference in ion transfer rate and volume expansion during the charging/ discharging process, further suggesting the structural and component advantages for the Sn/CoSn x @C anode materials. 31,51 The initial galvanostatic discharge/charge profile of Sn/ CoSn x @C at 1 A g −1 shows a long plateau region that is consistent with the redox peaks in the CV curves, and high initial discharge/charge capacities of 2006.6 and 1108.6 mAh g −1 can be provided (Figure S14), which are much higher than that of SnO 2 (1991/1080.3 mAh g −1 ), Sn/SnO 2 @C (1918.5/ 1172.4 mAh g −1 ), and Sn/SnO 2 @C (1415.5/774.3 mAh g −1 ). The Coulombic efficiency (CE) of the initial cycle for SnO 2 , Sn/SnO 2 @C, CoSn x @C, and Sn/CoSn x @C is 52.58%, 61.11%, 54.26%, and 55.25%, respectively.…”

“…Besides component controlling, it has been demonstrated that 1D hollow structures can effectively improve the lithium storage performance, which not only mitigates the large volume variations but also improves the initial coulomb efficiency of the battery, leading to improved cyclic life and rate performance. − In particular, the core–shell hollow structure can partially overcome the relatively low volumetric energy densities of hollow materials. − By constructing the Sn/SnO 2 @C composite hollow nanofibers with a multiwall structure, a high specific capacity of 963 mAh g –1 after 2000 cycles at a current density of 1 A g –1 and a reversible capacity of 508.2 mAh g –1 after 2000 cycles at 5 A g –1 were achieved . More importantly, the assembly of different active materials can yield unique synergies for enhanced electrical conductivity and structural stability. , For example, MOF crystals and their derivatives that have unique structural and component advantages have been widely used as electrode materials. − By assembling MOFs with SnO 2 , superior lithium storage performance can be achieved, which is attributed to the unique features of the MOF layer. , Also, our group has confirmed that assembling the MOF crystals into 1D structures can effectively enhance electrochemical performance. − …”

Tailoring the shell thickness of yolk–shell structured carbon microspheres: applications in metal selenide and carbon composite microspheres for enhanced sodium ion storage properties

“…These strategies include selective etching, templating assembly, carbon combustion, Ostwald ripening, galvanic replacement, and the Kirkendall effect, among others, and have contributed to the growing commercial interest in yolk-shell structured materials. [10][11][12][13][14][15] When considering yolk-shell structures as anode materials from a structural standpoint, outer shells play a dual role by providing structural robustness and preventing agglomeration of active materials, thereby maintaining the stability of SEI (solid electrolyte interphase) layers. 16,17 In particular, when the outer shell is made of pure carbon or a composite of metal compound nanocrystals, it enhances both electrical conductivity and structural exibility.…”

Controllable Synthesis of Carbon Yolk‐Shell Microsphere and Application of Metal Compound–Carbon Yolk‐Shell as Effective Anode Material for Alkali‐Ion Batteries

“…These samples had different porosities and yolk ratios, which influenced the electrolyte wetting, K + diffusion distance, and reversible adsorption of K + in K-ion batteries (KIBs).Recently, highly porous yolk-shell carbon materials with nanostructures were utilized as reservoirs for ultrafine nanocrystals. [13][14][15][16][17][18] Hierarchical micro-and mesoporous carbon materials could infiltrate ultrasmall chalcogen (sulfur or selenium) components and be applied to cathode materials for lithium-chalcogen batteries. Chen et al synthesized multishelled hollow carbon nanosphere-encapsulated sulfur composites with a high sulfur loading (86 wt%) using aqueous emulsions and in situ sulfur impregnation.…”