Researchers at India’s Tata Institute of Fundamental Research (TIFR) have developed a compact lithium-ion battery with photosensitive materials that can be directly recharged with solar energy.
According to the scientists, previous efforts to channel solar energy to recharge batteries used photovoltaic cells and batteries as separate entities. Solar energy, thus, was converted by the photovoltaic cells into electrical energy that was consequently stored as chemical energy in the batteries. The energy stored in these batteries was then used to power electronic devices.
But this relay of energy from one component to the other, that is, from the photovoltaic cell to the battery, led to energy losses. To address this issue, the team at TIFR started to explore the use of photosensitive components inside batteries themselves.
At the same time, the group decided that it was necessary to tackle some of the most common pitfalls of solar batteries, namely, their reduced ability to harness enough solar energy as time passes; their use of organic electrolytes, which may corrode the photosensitive organic component inside a battery, and the formation of side products that hinder the sustained performance of a battery in the long term.
Scientists at TIFR began exploring new photosensitive materials which can also incorporate lithium and build a solar battery that would be leak-proof and operate efficiently in ambient conditions.
In a paper published in the journal Nano-Micro Small, the team explains that solar batteries which have two electrodes usually include a photosensitive dye in one of the electrodes physically mixed with a stabilizing component which helps drive the flow of electrons through the battery. The scientists found that this solar battery, which was assembled from scratch, operates well when exposed to simulated solar light. “While this solar battery achieves a higher interaction of photosensitive material with light, it is yet to achieve the generation of optimum levels of current to fully recharge a lithium-ion battery,” they said in a media statement.