Low Cost Na-ion Based Solid Electrolytes and Organic Electrodes for Grid Storage

Yan YaoAssociate Professor of Electrical Engineering and

Texas Center for SuperconductivityUniversity of Houston

Workshop on Non-aqueous Flow BatteriesSanta Fe, NM. Jan. 29, 2019

2

Electrolyte dictated materials design for organic electrode materialsAqueouselectrolyte

SolidNaelectrolyte Non-aqueousMgelectrolyte

3

Na solid electrolytes as potential membranes for NRFBs

Dense solid electrolytes may function as membranes for NRFBs - single ion conductors - no cross-cover issues- Chemically stable S.H.Moonetal.RSCAdv.,2013,3,9095–9116

Glassy sulfide electrolyte

β''-Al2O3 electrolyte

4

Unfavorable electrode-electrolyte interfaceMechanical:Contact loss

Electrochemical:Irreversible resistive layerChemical:

Chemical reaction

Carbon

Challenges in cathode-solid sulfide electrolyte interfaceI. Irreversible resistive layer

J. Janek et al. J. Mater. Chem. A., 2017, 5, 22750

II. Mechanical contact loss

NMC-811

J. Janek et al. Chem. Mater., 2017, 29, 5574

5

Cathode materials in all-solid-state sulfide electrolyte batteries

Observed Theoretical

Stab

le W

indo

w o

f Su

lfide

SSE

sD

ecom

posi

tion

of

Sulfi

de S

SEs

Na2/3Co2/3Mn1/3O2

NaCrO2

Na3V2(PO4)3

NaFePO4

Na-TiS2Na4C6O6

0 50 100 150 200 250 3001

2

3

4

Pote

ntia

l (V

vs. N

a+ /Na)

Specific capacity (mAh g-1)

700500100 300 (Wh kg-1)

Ø Most intercalation cathodes operate at potentials above the anodic decomposition potential of SSEs (low capacity and 10-50 cycles)

Ø Solution: High-capacity organic cathodes with moderate redox potentialØ Na4PTO 90% capacity retention after 500 cycles at a capacity of 300 mAh/g

6

Organic cathodes with unprecendented cycle life

Na2C6O6 Na4C6O6

0 50 100 150 2000.0

0.6

1.2

1.8

2.4

Efficiency (%)

Pote

ntia

l (V

vs. N

a 15S

n 4)

Specific capacity (mAh g-1)

1st 10th

50th 100th

0.1C

0 20 40 60 80 1000

50100150200

Charging Discharging

Cap

acity

(mAh

g-1

)

Cycle number40

60

80

100

Na4PTOPTO

Chi et al., Angew. Chem. Int. Ed., 2018, 57, 2630;Fang, Yao, under review

0 100 200 300 4000.0

0.5

1.0

1.5

2.0

2.5

3.0

Pote

ntia

l (V

vs. N

a 15Sn

4)Specific capacity (mAh g-1)

1st 2nd

20th

50th

100th

0 100 200 300 400 500100

200

300

400

500

Charging Discharging

Spec

ific c

apac

ity (m

Ah g

-1)

Cycle number

80

85

90

95

100

105

Coul

ombi

c ef

ficie

ncy

(%)

7

Intimate contact between organic cathodes and electrolytes

Fresh

Cycled

J. Janek et al. Chem. Mater., 2017, 29, 5574

PTO:4.2GPaNa3PS4:10GPaNMC:150GPa

Fang,Yao,submitted

8

Formation of reversible resistive layer at cathode-solid interface

Moderate redox potential of organic cathodes that aligns with stable window of sulfide electrolytes.

NMC-811

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✕

✕

9

Acknowledgements

Collaborators

Funding SupportAqueous batteryü DOE/ARPA-Eü Research Corp. Solid batteryü DOE/ARPA-Eü DOE/EERE (Battery500)ü NASAMg batteryü ONR YIP ü NSF

Thanks to the organizers, the funding agency, and the audience for your attention.