SnO₂ Nanosheets Anchored on a 3D, Bicontinuous Electron and Ion Transport Carbon Network for High-Performance Sodium-Ion Batteries

Abstract

Here, we demonstrate the in situ growth of SnO2 nanosheets on a freestanding carbonized eggshell membrane (CEM), which provides three-dimensional, bicontinuous electron and ion transport pathways through a massively interconnected carbon fiber skeleton and interpenetrated pore network, respectively. This CEM has other advantages such as the ability to alleviate mechanical stress during cycling as a buffer matrix. When used as an additive-free anode in a sodium-ion battery, SnO2 nanosheets can realize a complete electrochemical reaction and maintain good cycling stability with the help of a CEM. For instance, SnO2 nanosheets delivered a high reversible capacity of 656 mA h g–1 in the 5th cycle at 0.1 A g–1, approaching 98% of its theoretical specific capacity, and maintained a high reversible specific capacity of 420 mA h g–1 after 200 cycles at 0.2 A g–1.

Rational Design of Core‐Shell Structured C@SnO2@CNTs Composite with Enhanced Lithium Storage Performance

“…In the high‐resolution Sn 3d spectrum (Figure a), the two strong peaks with binding energy gap of 8.4 eV are assigned to Sn 3d 5/2 and Sn 3d 3/2 , demonstrating that tin exists in the Sn 4+ ‐O state without other valence . The O 1s spectra of all samples (Figure b) can be resolved into three peaks centered about 530.5 eV, 532 eV and 533.4 eV, corresponding to Sn−O, C=O and C−O−C/−OH . In general, the O elements in the composite is regarded from SnO 2 and oxygen functional groups on CNTs.…”

“…[52] The O 1s spectra of all samples (Figure 3b) can be resolved into three peaks centered about 530.5 eV, 532 eV and 533.4 eV, corresponding to SnÀ O, C=O and CÀ OÀ C/À OH. [53] In general, the O elements in the composite is regarded from SnO 2 and oxygen functional groups on CNTs. When the mass ratio of CNTs decrease gradually in three samples (TG results), the relative content of SnO 2 should increase.…”

Recent Progress of Electrochemical Energy Devices: Metal Oxide–Carbon Nanocomposites as Materials for Next-Generation Chemical Storage for Renewable Energy

“…Fe2O3, one of the metal oxides applicable to sodium-ion batteries, has the following reaction (Equation 3 In the case of a CNT (1D structure) or graphene (2D structure), a metal-oxide composite with short CNTs or graphene with a small size may cause a high contact resistance. To address these issues, Zhao et al developed SnO2@CEM composites by growing SnO2 nanosheets on a carbonized eggshell membrane (CEM) with a porous structure as a matrix to improve the 1D and 2D structures [94]. Firstly, these 3D hierarchical structures also lead to an enhanced electric conductivity.…”

Energy Harvesting and Storage by Water Infiltration of Eggshell Membrane

“…Recently, utilizing eggshell membrane (ESM) as a biological material for electrochemical applications has been reported . For example, carbonized ESM was used as a natural polysulfide reservoir in Li–S batteries which achieved a high discharge capacity of 1327 mA h g −1 and high sulfur loading of 3.2 mg cm −2 .…”

“…Recently, utilizing eggshell membrane (ESM) as a biological material for electrochemical applications has been reported. [11][12][13][14][15][16][17][18][19][20] For example, carbonized ESM was used as a natural polysulfide reservoir in Li-S batteries which achieved a high discharge capacity of 1327 mA h g À1 and high sulfur loading of 3.2 mg cm À2 . [15] Additionally, carbonized ESM was used to form the counter electrode for dyesensitized solar cells which processed improved open-circuit voltage and a competitive efficiency due to the microporerich, hierarchically porous microstructure of ESM.…”