Nano‐single‐crystal‐constructed submicron MnCO₃ hollow spindles enabled by solid precursor transition combined Ostwald ripening in situ on graphene toward exceptional interfacial and capacitive lithium storage

Abstract

Hollow structuring has been identified as an effective strategy to enhance the cycling stability of electrodes for rechargeable batteries due to the outstanding volume expansion buffering efficiency, which motivates ardent pursuing on the synthetic approaches of hollow materials. Herein, an intriguing route, combining solid precursor transition and Ostwald ripening (SPTOR), is developed to craft nano single‐crystal (SC)‐constructed MnCO3 submicron hollow spindles homogeneously encapsulated in a reduced graphene oxide matrix (MnCO3 SMHSs/rGO). It is noteworthy that the H‐bonding interaction between Mn3O4 nanoparticles (NPs) and oxygen‐containing groups on GO promotes uniform anchoring of Mn3O4 NPs on GO, mild reductant ascorbic acid triggers the progressive solid‐to‐solid transition from Mn3O4 NPs to MnCO3 submicron solid spindles (SMSSs) in situ on GO, and the Ostwald ripening process induces the gradual dissolution of interior polycrystals of MnCO3 SMSSs and subsequent recrystallization on surface SCs of MnCO3 SMHSs. Remarkably, MnCO3 SMHSs/rGO delivers a 500th lithium storage capacity of 2023 mAh g−1 at 1000 mA g−1, which is 10 times higher than that of MnCO3 microspheres/rGO fabricated from a conventional Mn2+ salt precursor (202 mAh g−1). The ultrahigh capacity and ultralong lifespan of MnCO3 SMHSs/rGO can be primarily attributed to the superior reaction kinetics and reversibility combined with exceptional interfacial and capacitive lithium storage capability, enabled by the fast ion/electron transfer, large specific surface area, and robust electrode pulverization inhibition efficacy. Moreover, fascinating in‐depth lithium storage reactions of MnCO3 are observed such as the oxidation of Mn2+ in MnCO3 to Mn3+ in charge process after long‐term cycles and the further lithiation of Li2CO3 in discharge process. As such, the SPTOR approach may represent a viable strategy for crafting various hollow functional materials with metastable nanomaterials as precursors.

1T-VS2@V2O3 Synergistic Nanoarchitecture-Based Lamellar Clusters as the High Conductivity Cathodes of Thermal Batteries

“…This interface interaction is beneficial to ion adsorption and increases the electroactive site to prevent the structural degradation of the electrode material . Short ion transfer distances of single-crystalline and high conductivity of the layer for fast Li + /e – transfer rates …”

“…39 Short ion transfer distances of singlecrystalline and high conductivity of the layer for fast Li + /e − transfer rates. 40 EIS measurements have also been conducted on assembled thermal batteries with 1T-VS 2 lamellar clusters as cathode materials before and after discharge at 500 °C (Figure 6i). It can be seen from the curve that the overall internal resistance of the thermal battery slightly increases from 0.32 to 0.39 Ω after discharge, indicating that the internal resistance of the discharge product will not cause battery polarization.…”

Hybrid CuSn nanosphere-functionalized Cu/Sn co-doped hollow carbon nanofibers as anode materials for sodium-ion batteries

“…However, the prospect for the development of LIBs is severely hampered by the high price of metal lithium and the scarcity of lithium resources. [1][2][3] Sodium-ion batteries (SIBs) are a potential alternative to LIBs and several SIBs with different anode materials have been reported because of the rich natural resources and low cost of sodium. [4][5][6][7] Compared with Li + , Na + possesses a larger ionic radius, higher molar mass and a less favorable redox potential.…”

A bimetallic metal–organic framework derived MnS/CoS@C heterostructure with enhanced sodium-ion storage

“…(1) Constructing micro/nanostructures with interior space, which can efficiently accelerate ion/electron migration and alleviate volume changes; (2) forming composites with conductive heteroatom (such as S, N, and P) doped carbonous materials, which can promote charge transport, maintain structural integrity, and impede the dissolution of polysulfides. 8,[14][15][16][17][18][19] So far, most of the work has focused on the two perspectives mentioned above, with the aim of promoting the diffusion kinetics. As expected, significant progress has been made in recent years on MnS-based anode materials, but the comprehensive properties are still unsatisfactory.…”