German China

Japan: Material Science

Self-Healing Polymers Prevent Leakage of Lead from Solar Cells

| Editor: Alexander Stark

Researchers exposed the solar cells to brutal conditions to simulate worst-case weather scenarios. Adding a self-healing epoxy resin polymer to the cell minimized the leakage of lead from the cell.
Gallery: 3 Pictures
Researchers exposed the solar cells to brutal conditions to simulate worst-case weather scenarios. Adding a self-healing epoxy resin polymer to the cell minimized the leakage of lead from the cell. (Source: Oist)

A protective layer of epoxy resin helps prevent the leakage of pollutants from perovskite solar cells (PSCs), report scientists from the Okinawa Institute of Science and Technology Graduate University (Oist). Adding a “self-healing” polymer to the top of a PSC can radically reduce how much lead it discharges into the environment. This gives a strong boost to prospects for commercializing the technology.

Okinawa/Japan — With atmospheric carbon dioxide levels reaching their highest recorded levels in history, and extreme weather events continuing to rise in number, the world is moving away from legacy energy systems relying on fossil fuels towards renewables such as solar. Perovskite solar technology is promising, but one key challenge to commercialization is that it may release pollutants such as lead into the environment — especially under extreme weather conditions.

Although PSCs are efficient at converting sunlight into electricity at an affordable cost, the fact that they contain lead raises considerable environmental concern. While so-called ‘lead-free’ technology is worth exploring, it has not yet achieved efficiency and stability comparable to lead-based approaches. Finding ways of using lead in PSCs while keeping it from leaking into the environment, therefore, is a crucial step for commercialization, explains Professor Yabing Qi, head of the Energy Materials and Surface Sciences Unit, who led the study, published in Nature Energy.

Non-Toxic and Efficient Films for Solar Cells

Japan: Bismuth Sulfide

Non-Toxic and Efficient Films for Solar Cells

20/09/2018 - Researchers at Osaka University have developed a two-step process that can produce materials for optoelectronic devices such as solar cells with good morphological properties and excellent photoresistor performance. The films are based on bismuth sulfide which is non-toxic. read...

Testing to Destruction

Qi’s team, supported by the Oist Technology Development and Innovation Center’s Proof-of-Concept Program, first explored encapsulation methods for adding protective layers to PSCs to understand which materials might best prevent the leakage of lead. They exposed cells encapsulated with different materials to many conditions designed to simulate the sorts of weather to which the cells would be exposed in reality.

They wanted to test the solar cells in a worst-case weather scenario, to understand the maximum lead leakage that could occur. First, they smashed the solar cells using a large ball, mimicking extreme hail that could break down their structure and allow lead to be leaked. Next, they doused the cells with acidic water, to simulate the rainwater that would transport leaked lead into the environment.

Using mass spectroscopy, the team analyzed the acidic rain to determine how much lead leaked from the cells. They found that an epoxy resin layer provided minimal lead leakage — orders of magnitude lower than the other materials.

Researchers exposed the solar cells to brutal conditions to simulate worst-case weather scenarios. Adding a self-healing epoxy resin polymer to the cell minimized the leakage of lead from the cell.

Enabling Commercial Viability

Epoxy resin also performed best under a number of weather conditions in which sunlight, rainwater and temperature were altered to simulate the environments in which PSCs must operate. In all scenarios, including extreme rain, epoxy resin outperformed rival encapsulation materials.

Epoxy resin worked so well due to its “self-healing” properties. After its structure is damaged by hail, for example, the polymer partially reforms its original shape when heated by sunlight. This limits the amount of lead that leaks from inside the cell. This self-healing property could make epoxy resin the encapsulation layer of choice for future photovoltaic products.

Beyond lead leakage, another challenge will be to scale up perovskite solar cells into perovskite solar panels. While cells are just a few centimeters long, panels can span a few meters, and will be more relevant to potential consumers. The team will also direct their attention to the long-standing challenge of renewable energy storage.

Scientists Develop Electron Beam Patterning for Oleds

Germany: Micropatterning Approach

Scientists Develop Electron Beam Patterning for Oleds

08/08/2018 - Oled microdisplays are increasingly establishing themselves in wearables and data glasses. In order to meet the requirements for higher efficiency, higher contrast, and higher resolutions in these applications, Fraunhofer FEP scientists have developed a new micropatterning approach for Oleds on silicon substrates. read...

Comments are being loaded ....

Leave a comment

The comment is checked by an editor and will be released soon.

  1. Avatar
    Avatar
    Edited by at
    Edited by at
    1. Avatar
      Avatar
      Edited by at
      Edited by at

Comments are being loaded ....

Report comment

Kommentar Freigeben

Der untenstehende Text wird an den Kommentator gesendet, falls dieser eine Email-hinterlegt hat.

Freigabe entfernen

Der untenstehende Text wird an den Kommentator gesendet, falls dieser eine Email-hinterlegt hat.

copyright

This article is protected by copyright. You want to use it for your own purpose? Contact us via: support.vogel.de/ (ID: 45986325 / Laborpraxis Worldwide)