## Example 2: Ni Foam and CVD Graphene Foam-Based Conductive Porous Layers on Ni Foam Templates 

The procedure for producing CVD graphene foam was adapted from that disclosed in open literature: Chen, Z. et al. "Three-dimensional flexible and conductive interconnected graphene networks grown by chemical vapor deposition," Nature Materials, 10, 424-428 (2011 ). Nickel foam, a porous structure with an interconnected 3D scaffold of nickel was chosen as a template for the growth of graphene foam. Briefly, carbon was introduced into a nickel foam by decom› posing CH$_{4 }$ at 1,000° C. under ambient pressure, and gra› phene films were then deposited on the surface of the nickel foam. Due to the difference in the thermal expansion coef› ficients between nickel and graphene, ripples and wrinkles were formed on the graphene films. Four types of foams made in this example were used as a current collector in the presently invented lithium batteries: Ni foam, CVD gra› phene-coated Ni form, CVD graphene foam (Ni being etched away), and conductive polymer bonded CVD gra- phene foam. 

In order to recover (separate) graphene foam from the supporting Ni foam, Ni frame was etched away. In the procedure proposed by Chen, et al., before etching away the nickel skeleton by a hot HCI ( or FeCl$_{3}$ ) solution, a thin layer of poly (methyl methacrylate) (PMMA) was deposited on the surface of the graphene films as a support to prevent the graphene network from collapsing during nickel etching. After the PMMA layer was carefully removed by hot acetone, a fragile graphene foam sample was obtained. The use of the PMMA support layer was considered critical to preparing a free-standing film of graphene foam. Instead, we used a conducting polymer as a binder resin to hold gra› phene together while Ni was etched away. It may be noted that the CVD graphene foam used herein is intended as a foamed current collector to accommodate a suspension of active material dispersed in a liquid electrolyte. For instance, liquid or gel slurry of hard carbon nano particles dispersed in a liquid or gel electrolyte for the anode, and slurry of graphene-supported NaFePO$_{4 }$ nano particles dispersed in a liquid or gel electrolyte in the cathode. 

## Example 3: Graphitic Foam-Based Conductive Porous Layers from Pitch-Based Carbon Foams 

Pitch powder, granules, or pellets are placed in a alumi› num mold with the desired final shape of the foam. Mit› subishi ARA-24 mesa-phase pitch was utilized. The sample is evacuated to less than 1 torr and then heated to a temperature approximately 300° C. At this point, the vacuum was released to a nitrogen blanket and then a pressure ofup to 1,000 psi was applied. The temperature of the system was then raised to 800° C. This was performed at a rate of 2 degree C./min. The temperature was held for at least 15 minutes to achieve a soak and then the furnace power was turned off and cooled to room temperature at a rate of approximately 1.5 degree C./min with release of pressure at a rate of approximately 2 psi/min. Final foam temperatures were 630° C. and 800° C. During the cooling cycle, pressure is released gradually to atmospheric condi› tions. The foam was then heat treated to 1050° C. (carbon› ized) under a nitrogen blanket and then heat treated in separate runs in a graphite crucible to 2500° C. and 2800° C. (graphitized) in Argon. 

## Example 4: Some Examples of Electrolytes Used 

Preferred non-lithium alkali metal salts include: sodium perchlorate (NaCIO$_{4}$ ), potassium perchlorate (KCIO$_{4}$ ), 

sodium hexafluorophosphate (NaPF $_{6}$ ), potassium hexafluo› rophosphate (KPF $_{6}$ ), sodium borofluoride (NaBF 4 ), potas› sium borofluoride (KBF 4 ), sodium hexafluoroarsenide, potassium hexafluoroarsenide, sodium trifluoro-metasul› fonate (NaCF $_{3}$SO$_{3}$ ), potassium trifluoro-metasulfonate (KCF$_{3}$ SO$_{3}$), bis-trifluoromethyl sulfonylimide sodium (NaN (CF $_{3}$ SO$_{2}$ ) 2 ), and bis-trifluoromethyl sulfonylimide potas› sium [KN(CF$_{3}$SO$_{2}$) 2 ]. 

For aqueous electrolyte, sodium salt or potassium salt is preferably selected from Na$_{2}$ SO$_{4}$ , K$_{2}$ SO$_{4}$ , a mixture thereof, NaOH, KOH, NaCl, KC!, NaF, KF, NaBr, KBr, NaI, KI, or a mixture thereof. The salt concentrations used in the present study were from 0.3M to 3.0 M (most often 0.5M to 2.0M). 

A wide range oflithium salts can be added as a second salt (a modifier additive) dissolved in an organic liquid solvent ( alone or in a mixture with another organic liquid or an ionic liquid), if so desired. The following are good choices for lithium salts that tend to be dissolved well in selected organic or ionic liquid solvents: lithium borofluoride (LiBF 4 ), lithium trifluoro-metasulfonate (LiCF$_{3}$ SO$_{3}$), lithium bis-trifluoromethyl sulfonylimide (LiN(CF$_{3}$SO$_{2}$ ) $_{2 }$or LITFSI), lithium bis( oxalato )borate (LiBOB), lithium oxalyldifluoroborate (LiBF $_{2}$C$_{2}$O$_{4}$ ), and lithium bisperfluo› roethy-sulfonylimide (LiBETI). A good electrolyte additive for helping to stabilize Li metal is LiNO$_{3}$ • Particularly useful ionic liquid-based lithium salts include: lithium bis(trifluoro methanesulfonyl)imide (LiTFSI). 

Preferred organic liquid solvents include: ethylene car› bonate (EC), dimethyl carbonate (DMC), methylethyl car› bonate (MEC), diethyl carbonate (DEC), propylene carbon› ate (PC), acetonitrile (AN), vinylene carbonate (VC), ally! ethyl carbonate (AEC), 1,3-dioxolane (DOL), 1,2-dime› thoxyethane (DME), tetraethylene glycol dimethylether (TEGDME), Poly(ethylene glycol) dimethyl ether (PEGDME), diethylene glycol dibutyl ether (DEGDBE), 2-ethoxyethyl ether (EEE), hydrofloroether ( e.g. TPTP), sulfone, and sulfolane. 

Preferred ionic liquid solvents may be selected from a room temperature ionic liquid (RTIL) having a cation selected from tetraalkylammonium, alkylpyridinium, dialkyl-pyrrolidinium, or dialkylpiperidinium. The counter anion is preferably selected from BF 4 -, B(CN) 4 -, CF $_{3}$CO$_{2 }$ -, CF$_{3}$SO$_{3}$-, N(SO$_{2}$CF$_{3}$ ) 2 -, N(COCF$_{3}$)(SO$_{2}$CF$_{3}$ t, or N (SO$_{2}$F)$_{2 }$- . Particularly useful ionic liquid-based solvents include N-n-butyl-N-ethylpyrrolidinium bis(trifluorometh› ane sulfonyl)imide (BEPyTFSI), N-methyl-N-propylpiperi› dinium bis(trifluoromethyl sulfonyl)imide (PP $_{13 }$TFSI), and N,N-diethyl-N-methyl-N-(2-methoxyethyl) anrmonium bis ( trifluoromethy lsulfonyl )imide. 

## Example 4: Preparation of Graphene Oxide (GO) and Reduced Graphene Oxide (RGO) Nano Sheets from Natural Graphite Powder 

Natural graphite from Huadong Graphite Co. (Qingdao, China) was used as the starting material. GO was obtained by following the well-known modified Hummers method, which involved two oxidation stages. In a typical procedure, the first oxidation was achieved in the following conditions: 1100 mg of graphite was placed in a 1000 mL boiling flask. Then, 20 g of K$_{2}$S$_{2}$O$_{8}$ , 20 g of P$_{2}$O$_{5}$ , and 400 mL of a concentrated aqueous solution ofH$_{2}$ SO$_{4 }$ (96%) were added in the flask. The mixture was heated under reflux for 6 hours and then let without disturbing for 20 hours at room tem- perature. Oxidized graphite was filtered and rinsed with abundant distilled water until neutral pH. A wet cake-like material was recovered at the end of this first oxidation. 

