Solar batteries capable of harvesting sunlight and storing solar energy present an attractive vista to transition our energy infrastructure into a sustainable future. We present an integrated, fully earth-abundant solar battery design based on a bifunctional (light absorbing and charge storing) carbon nitride (K-PHI) photoanode, combined with all-organic hole transfer and storage materials. An internal ladder-type hole transfer cascade via a hole transport layer is used to shuttle the photogenerated holes to the PEDOT:PSS cathode. This concept differs from previous designs such as light-assisted battery schemes or photocapacitors and allows charging with only light or light-assisted during electrical charging and discharging, thus substantially increasing the energy output of the cell. Compared to battery operation in the dark, light-assisted (dis)charging increases charge output by 243 %, thereby increasing the electric coulombic efficiency from 68.3 % in the dark to 231 %, leading to energy improvements of 94.1 % under illumination.
@article{arxiv.2209.02530,
title = {An Integrated Solar Battery based on a Charge Storing 2D Carbon Nitride},
author = {Andreas Gouder and Filip Podjaski and Alberto Jiménez-Solano and Julia Kröger and Yang Wang and Bettina V. Lotsch},
journal= {arXiv preprint arXiv:2209.02530},
year = {2022}
}