Green and Facile Fabrication of Hollow Porous MnO/C Microspheres from Microalgaes for Lithium-Ion Batteries

Abstract

Hollow porous micro/nanostructures with high surface area and shell permeability have attracted tremendous attention. Particularly, the synthesis and structural tailoring of diverse hollow porous materials is regarded as a crucial step toward the realization of high-performance electrode materials, which has several advantages including a large contact area with electrolyte, a superior structural stability, and a short transport path for Li(+) ions. Meanwhile, owing to the inexpensive, abundant, environmentally benign, and renewable biological resources provided by nature, great efforts have been devoted to understand and practice the biotemplating technology, which has been considered as an effective strategy to achieve morphology-controllable materials with structural specialty, complexity, and related unique properties. Herein, we are inspired by the natural microalgae with its special features (easy availability, biological activity, and carbon sources) to develop a green and facile biotemplating method to fabricate monodisperse MnO/C microspheres for lithium-ion batteries. Due to the unique hollow porous structure in which MnO nanoparticles were tightly embedded into a porous carbon matrix and form a penetrative shell, MnO/C microspheres exhibited high reversible specific capacity of 700 mAh g(-1) at 0.1 A g(-1), excellent cycling stability with 94% capacity retention, and enhanced rate performance of 230 mAh g(-1) at 3 A g(-1). This green, sustainable, and economical strategy will extend the scope of biotemplating synthesis for exploring other functional materials in various structure-dependent applications such as catalysis, gas sensing, and energy storage.

Tuning ultrafine manganese oxide nanowire synthesis seeded by Si particles and its superior Li storage behaviors

“…The pyrolysis carbonaceous matrix acts as not only a volume buffer but also a conductive network when the composite of MnO and matrix is used as anode material in the LIBs during the charge-discharge process. [10][11][12]25,26 Moreover, a thermogravimetry analysis was performed to further illustrate the carbon content of the composite (Supplementary Figure S5). The first weight loss was~1.4% and occurred below 200°C, which can be attributed to the desorption of absorbed water.…”

“…[1][2][3][4] MnO is among the well-known technologically important materials used in diverse application areas, including in electronics, 5 sensors, 6 magnetic storage media, 7 optical 8 and catalysis, 9 especially lithium-ion batteries. [10][11][12][13][14][15][16][17][18] Several techniques for the synthesis of MnO 1D structures have been made available. Guo and co-workers 11 designed an MnO/carbon nanopeapod nanostructure with an internal void space by annealing the MnO precursor/polydopamine core/shell nanostructure.…”

Reconstruction of Mini‐Hollow Polyhedron Mn2O3 Derived from MOFs as a High‐Performance Lithium Anode Material

“…Manganese oxides materials have shown great potential application as energy materials, such as water oxidation and oxygen reduction,1, 2, 3 electrochemical capacitors,4, 5 lithium–O 2 batteries,6 and lithium‐ion batteries (LIBs) 7, 8, 9, 10, 11, 12, 13, 14, 15. Owing to their high specific theoretical capacity, low cost, and environmentally benign nature, manganese oxides (MnO x , 1 ≤ x ≤ 2) are believed to be the most promising alternative anode materials for next generation LIBs 11, 13, 16, 17.…”

“…Owing to their high specific theoretical capacity, low cost, and environmentally benign nature, manganese oxides (MnO x , 1 ≤ x ≤ 2) are believed to be the most promising alternative anode materials for next generation LIBs 11, 13, 16, 17. Moreover, the low operating voltages (1.3–1.5 V for lithium extraction) and small voltage hysteresis (<0.8 V) endow these materials with higher output voltage and higher energy density 14, 15, 18.…”

“…The high‐angle annular dark‐field scanning transmission electron microscope (HAADF‐STEM) image (Figure 1d) confirms the hollow structure with a thick shell and mini‐hollow cavity, different from the conventional hollow structure with a thin shell and large‐hollow cavity 31, 38, 39, 40. Obviously, the mini‐hollow cavity could provide the space to hold the inward volume expansion 13. The distances of the lattice fringes in Figure 1e are around 2.72 and 3.84 Å, corresponding to the (222) and (211) planes of cubic Mn 2 O 3 9…”