Emulsion-templated bicontinuous carbon network electrodes for use in 3D microstructured batteries

Abstract

High surface area carbon foams were prepared and characterized for use in 3D structured batteries. Two potential applications exist for these foams: firstly as an anode and secondly as a current collector support for electrode materials. The preparation of the carbon foams by pyrolysis of a high internal phase emulsion polymer (polyHIPE) resulted in structures with cage sizes of $25 mm and a surface area enhancement per geometric area of approximately 90 times, close to the optimal configuration for a 3D microstructured battery support. The structure was probed using XPS, SEM, BET, XRD and Raman techniques; revealing that the foams were composed of a disordered carbon with a pore size in the <100 nm range resulting in a BET measured surface area of 433 m 2 g À1 . A reversible capacity exceeding 3.5 mA h cm À2 at a current density of 0.37 mA cm À2 was achieved. SEM images of the foams after 50 cycles showed that the structure suffered no degradation. Furthermore, the foams were tested as a current collector by depositing a layer of polyaniline cathode over their surface. High footprint area capacities of 500 mA h cm À2 were seen in the voltage range 3.8 to 2.5 V vs. Li and a reasonable rate performance was observed.

Graphene-reinforced carbon composite foams with improved strength and EMI shielding from sucrose and graphene oxide

“…Due to these exciting properties, carbon foams are considered for applications like thermal protection, heat exchangers, heat sink, EMI shielding, catalyst support, electrodes in batteries and fuel cells, host structure for phase change materials, etc. [3][4][5][6][7]. Fossil fuel-based precursors like coal-tar pitch [8], petroleum pitch [8,9], mesophase pitch [1,10,11], phenolformaldehyde resin, furfural resin, polyimide [12], cyanate ester resin [13], and polyarylacetylene [14] are conventionally used for the preparation of carbon foams.…”

Hierarchical self-assembled structures based on nitrogen-doped carbon nanotubes as advanced negative electrodes for Li-ion batteries and 3D microbatteries

“…These performances are remarkable, especially considering that the cycling is carried out at a current density of 0.3 mAcm À2 on rather thin electrode structures. Indeed, the values of the footprint area capacity are comparable with those of 3D carbon-network electrodes based on significantly thicker porous carbonaceous materials tested under similar cycling conditions [53].…”

Three-dimensional carbon foam supported tin oxide nanocrystallites with tunable size range: Sulfonate anchoring synthesis and high rate lithium storage properties

“…A monolithic polymer foam is prepared via a high internal phase emulsion polymerization (polyHIPE) method as described in our previous work [29]. As illustrated in Scheme 1, the polyHIPE is firstly sulfonated for dual purposes: 1) sulfonation prevents the depolymerization and stabilizes the macroporous structure during the carbonization of polymer at elevated temperatures; 2) chemically grafted sulfonate (RSO 3 À ) groups serve as active anchoring sites for tetravalent Sn 4þ via the electrostatic force when the sulfonated polymer is soaked in the precursor solution.…”

“…The synthetic procedure of the polyHIPE was described in our previous work [29]. In brief, The oil phase (the stoichiometric amount of styrene, DVB, VBC and Span 80 at pre-determined ratio) was mixed with the aqueous phase (6 mL water solution of 0.165 g stabilizing salt CaCl 2 .6H 2 O and 0.0150 g initiator K 2 S 2 O 8 ) to form an emulsion under constant stirring.…”