(33e) Environmentally Responsible Fabrication of Efficient Perovskite Solar Cells from Recycled Car Batteries

Environmentally Responsible
Fabrication of Efficient Perovskite Solar Cells

from Recycled Car Batteries

Po-Yen Chen^1,2*, Paula T. Hammond¹,
Angela M. Belcher³

¹Department of Chemical
Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139

²School of Engineering, Brown
University, Providence, RI 02912

³Department of Materials Science
and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139

Email: pychen@mit.edu

            Organolead
halide perovskite solar cells (PSCs) show great promise as a new large-scale
and cost-competitive photovoltaic technology. Power conversion efficiencies
over 15% to over 20% have been achieved within 18 to 36 months of development,
and thus perovskite materials have attracted great attention in photovoltaic
research. However, the manufacture of PSCs raises environmental concerns
regarding the over-production of raw lead ore, which has harmful health and
ecological effects. In this study, we have demonstrated an environmentally
responsible synthetic pathway to reuse car batteries for the fabrication of
efficient PSCs (Figure 1). Both the anodes and cathodes of car batteries
serve as material sources for the synthesis of lead iodide perovskite
materials. In contrast to the traditional lead extraction process, our
synthesis pathway from recycled battery materials occurs at a lower temperature
(600 degree C) and does not include the hazardous emission of lead vapor/dust
and CO₂ to the environment. The lead iodide perovskite materials
synthesized from car batteries and high-purity reagents demonstrate identical
material characteristics. The photovoltaic performance of the PSCs synthesized
by each route is the same, which demonstrates that the device quality does not
suffer from the materials sourced from spent car batteries. Also,
electrochemical impedance spectra (EIS) measurements reveal that each device
type displays the same resistances of electron recombination, indicating that
the electron-trans- port properties of the lead iodide perovskite are
identical. Finally, a simple economic analysis reveals that a single lead- acid
car battery can supply enough lead material for the fabrication of 709-m²
PSCs, which can provide enough electricity to power 30.2 US residential units
in Las Vegas, Nevada. With these techniques, the time required to find a lead
replacement for PSCs can be further increased. The environmentally responsible
fabrication is expected to be broadly applicable not only to the PSC technology
but also other applications.

Figure 1. Synthetic process of lead
iodide perovskite materials from a lead-acid car battery. The process includes
three steps: (1) harvesting material from the anodes and cathodes of a car battery
(red); (2) synthesizing PbI₂ from the collected materials (blue); (3)
depositing lead iodide perovskite nanocrystals (green).