Membrane-Free Battery for Harvesting Low-Grade Thermal Energy

Journal Article · Mon Oct 13 00:00:00 EDT 2014 · Nano Letters

DOI:https://doi.org/10.1021/nl5032106· OSTI ID:1385292

Yang, Yuan ^[1]; Loomis, James ^[1]; Ghasemi, Hadi ^[1]; Lee, Seok Woo ^[2]; Wang, Yi Jenny ^[1]; Cui, Yi ^[3]; Chen, Gang ^[1]

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1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Mechanical Engineering
2. Stanford Univ., CA (United States). Dept. of Materials Science and Engineering
3. Stanford Univ., CA (United States). Dept. of Materials Science and Engineering; SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Inst. for Materials and Energy Sciences

Efficient and low-cost systems are desired to harvest the tremendous amount of energy stored in low-grade heat sources (<100 °C). An attractive approach is the thermally regenerative electrochemical cycle (TREC), which uses the dependence of electrode potential on temperature to construct a thermodynamic cycle for direct heat-to-electricity conversion. By varying the temperature, an electrochemical cell is charged at a lower voltage than discharged; thus, thermal energy is converted to electricity. Recently, a Prussian blue analog-based system with high efficiency has been demonstrated. However, the use of an ion-selective membrane in this system raises concerns about the overall cost, which is crucial for waste heat harvesting. We report on a new membrane-free battery with a nickel hexacyanoferrate (NiHCF) cathode and a silver/silver chloride anode. The system has a temperature coefficient of -0.74 mV K^–1. When the battery is discharged at 15 °C and recharged at 55 °C, thermal-to-electricity conversion efficiencies of 2.6% and 3.5% are achieved with assumed heat recuperation of 50% and 70%, respctively. This work opens new opportunities for using membrane-free electrochemical systems to harvest waste heat.

• Research Organization: Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
• Grant/Contract Number: SC0001299; FG02-09ER46577; EE0005806; AC02-76SF00515
• OSTI ID: 1385292
• Journal Information: Nano Letters, Vol. 14, Issue 11; ISSN 1530-6984
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
low-grade thermal energy
battery
TREC
thermally regenerative electrochemical cycle
membrane-free
electrochemical systems