Multiple-Electron Aqueous Chunsheng Wang , Associate professor, - - PowerPoint PPT Presentation

Technology Overview Current Status

• Enlarging the cell voltage by expending

electrochemical window of aqueous electrolytes to 2.5V using highly concentrated electrolytes.

• Increasing the electrode capacity using multiple-

electron reactions

• Energy density goal: 150-200 Wh kg-1

Status:

• Fabricated a single-electron aqueous cell with

2.0V voltage, 100 Wh/kg energy density, >1000 cycle life.

• Developed a multiple-electron cathode with

capacity of 250 mAh/g. Next Technical Steps

• Develop a multiple-electron anode

Next Commercial Steps

• Contact Saft for commercialization

Help Need

• 6 month extension to develop multiple-electron

aqueous batteries

Multiple-Electron Aqueous Battery

TEAM: Chunsheng Wang, Associate professor, University of Maryland, cswang@umd.edu Kang Xu: Senior Chemist Army Research Lab

Project Statistics

Award Amount $610k Award Timeline March, 2014 -- March 2015 Next Stage Target $300k for aqueous cell with energy>150 Wh/g Collaborations Sought Saft America Inc.

2

2.0V Aqueous single-electron lithium ion batteries

Cycling performance of high-voltage aqueous Li-ion batteries 2.7V aqueous electrolyte (pH=7) Charge/discharge curves of 2.0V single-electron full cell. Capacity is based on the total mass of anode and cathode

3

Novel aqueous battery technologies beyond state-of-the-art aqueous Li-ion batteries

2.0V aqueous single-electron lithium ion batteries

4

Multiple-electron MnO2 Cathodes for Mg2+/H+ batteries

WE: MnO2, CE: active carbon Electrolyte: Mg(NO3)2-Mg(OH2) Current: 100 mA/g

50 100 150

• 0.6
• 0.5
• 0.4
• 0.3
• 0.2
• 0.1

0.0 E vs.Ag/AgCl (V) Capacity (mAh/g)

WE: MnO2 CE: active carbon RE: Ag/AgCl Electrolyte: 1M KOH-H2O

H+

Mg2+

20 40 60 80 100

• 0.6
• 0.4
• 0.2

0.0 0.2 0.4 E vs.Ag/AgCl (V) Discharge capacity(mAh/g)

200mA/g

79% capacity comes from Mg2+ insertion, the rest comes from H+ insertion

H+ Mg2+

WE: MnO2 CE: active carbon RE: Ag/AgCl Current: 200 mA/g Electrolyte: Mg(NO3)2-Mg(OH)2-H2O

5

Multiple-electron Mo3S4 Anodes for Mg2+/H+ batteries

Mg insertion/extraction behavior of Mo3S4 at 100 mA/g in 0.1M Mg(BH4)2/1.5M LiBH4/diglyme organic electrolyte Cycle stability of Mo3S4 for Mg insertion/extraction at 100 mA/g in 0.1M Mg(BH4)2/1.5M LiBH4/diglyme organic electrolyte

Project Status and Achievements

pH

2 4 6 8 10 12 14 16

Potential E/ V

• 2.5
• 1.5
• 0.5

0.5 1.5

• 3.0
• 2.0
• 1.0

0.0 1.0

• 2.5
• 1.5
• 0.5

0.5 1.5

• 3.0
• 2.0
• 1.0

0.0 1.0 H2 = 2H + 2e

• 2H2O = O2 + 4H

+ + 4e

• MgH2

Mg(OH)2 H2O Mg

Mg-M alloys MnO2 cathode

MgxMo3S4 anode Publications 1.

• T. Gao, F. Han, Y. Zhu, L.

Suo, C. Luo, K. Xu and C. Wang, Hybrid Mg2+/Li+ Battery with Long Cycle Life and High Rate Capability, Advanced Energy Materials, 2014, DOI: 10.1002/aenm.201401

• 507. Highlighted by

Materials View. 2.

• L. Suo, et al, High energy

aqueous Li-ion batteries. Submitted