DEVELOPING A SOLID 

ELECTROLYTE BY 

INFILTRATING 

NANOPOROUS SILICA 

WITH NaCB1 1H1 2

BY MAŁGORZATA (MAGGIE) PSUREK

THOMAS S. WOOTTON HIGH SCHOOL
• No liquid between anode and cathode • Conduct electricity through 

electrolytes – Possible solid electrolytes: Sodium 

salts

• Safer than liquid electrolyte batteries – not flammable – don’t spill: don’t damage device – don’t produce HF

SOLID 

ELECTROLYTE 

BATTERIES

http://www.androidauthority.com

Samsung Galaxy Note 7
Solid electrolyte: NaCB11H12

• Possible solid conductor: NaCB11H12

• Need a disordered state to conduct

– State transition occurs around 110 ̊c (383K)

• Too high temperature to be useful

• Salt + nonporous silica = conductive material at rt?
NANOPOROUS SILICA: SBA-15

• Silica (SiO2) that has very small (8nm) pores

• Putting salt in nanopores is a form of 

nanosizing

– Changes behavior: no bulk behavior

http://pubs.rsc.org

http://www.nature.com

Nanoporous silica under a Scanning Electron Microscope
DIFFERENTIAL SCANNING 

CALORIMETRY (DSC)

• Increases temperature of substance at a constant rate

• Needs more heat during order-disorder transition

– Phase change shows up as peak

DSC graph for wet sample of NaCB11H12
 

 

 

 

 

 

 

 

 

 

 

 

Instrument : NETZSCH STA 449F1... File : ...\9NaCB11H12+10SBA-15-inAl-He-21Jul2017-cycling01-320... Remark : Sample:9NaCB11H12+10SBA-15. Sample mass = 4.3 mg; crucible + lid = 39.7 mg. Mass of...

40 60 80 100 120

Temperature /°C

50

60

70

80

90

TG /%

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

DSC /(μV/mg)

Main 2017-07-26 14:27 User: ncnruser

[1.2]

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↓ exo

MAKING THE 

SAMPLES

• Mixed saturated solution of NaCB11H12

with SBA-15

– Solution concentration: 

143g NaCB11H12/100g H2O

– Various mass ratios

• Tested each with DSC

9:10

NaCB11H12 :SBA-15 sample DSC graph for NaCB11H12:SBA-15 sample (11:12, w/w)

DSC graph for NaCB11H12 :SBA-15 sample (9:10, w/w)
MASS RATIO PEAK AREA 

• Increased area under peak = increased transition energy

– Amount of NaCB11H12 (relative to silica) directly proportional with peak area

• Phase change = bulk behavior

– Require maximum salt without bulk behavior

Ratio by

mass

massNaCB11H12/

massSBA-15

Area under 

peak

1:0 undefined 45.76

9:4 2.26 46.19

3:2 1.5 30.33

7:6 1.16 17.6

11:12 0.919 8.321

9:10 0.9 0

y = 31.278x - 21.668

R2 = 0.9353

-10

0

10

20

30

40

50

60

Area peak/mass NaCB11H12

0 0.5 1 1.5 2 2.5 3

(in microVs/mgNaCB11H12)

massNaCB11H12/massSBA-15

Area under DSC peak of NaCB11H12 + SBA-15 

mixture
MEASURING 

CONDUCTIVITY: SET UP

• Electrolytic cell allows for conductivity testing

• Need to make pellet to put into cell

– Pelletizer presses molecules close together

• Larger batch to make pellet

– Needs to be dry—quartz vacuum tube

Photos by Erin Huang

3 zone tube furnace quartz vacuum tube

MEASURING CONDUCTIVITY

• Pelletized sample put into electrolytic cell

• Cell heated and cooled

– 273K - 423K (0 ̊c - 150  ̊c)

• Conductivity measured over temperature range

Electrolytic cell

pelletizer
RESULTS

• Electrochemical Impedance Spectroscopy

– Conductivity can be calculated from impedance

• Conductivity of new mixture v. conductivity of pure NaCB11H12

– 2 orders of magnitude more conductive at room temperature

-6

-5

-4

-3

-2

-1

0

273 293 313 333 353 373 393 413

LOG(Conductivity) (Log(S/cm))

Temperature (K)

Conductivity of NaCB11H12 and of NaCB11H12+SBA-15

NaCB11H12

NaCB11H12+SBA-15
CONCLUSION:

• NaCB11H12 below 110 ̊c (383K) poor conductivity

• NaCB11H12 above 110 ̊c (383K) very high conductivity

• NaCB11H12 combined with SBA-15 at room temperature conducts 100x than pure NaCB11H12 

– conductivity stays relatively constant form 293-413K.

NEXT STEPS:

• Test conductivity of pure SBA-15

• Test conductivity of NaCB11H12+SBA-15 in different proportions

• Use 4nm porous silica instead of 8nm porous silica (SBA-15)

• Add oversaturated solution to silica again after drying
ACKNOWLEDGEMENTS

Mentors: 

Terrence Udovic

Mirjana Dimitrievska

Juscelino Leão

Wan Si Tang

Paul Neves

Co-interns: 

Jacob Gurowitz

Erin Huang

SHIP Directors: 

Yamali Hernandez

Julie Borchers

Dan Neumann