An Integrated Solar Battery based on a Charge Storing 2D Carbon Nitride

TL;DR

This paper introduces a fully earth-abundant solar battery that combines a 2D carbon nitride photoanode with organic charge transfer materials, enabling efficient light-assisted energy storage and significantly boosting energy output compared to dark operation.

Contribution

It presents a novel integrated solar battery design utilizing a bifunctional carbon nitride photoanode and organic materials, enhancing energy output through light-assisted charging and discharging.

Findings

Light-assisted charging increases charge output by 243%.

Electric coulombic efficiency improves from 68.3% in dark to 231% under illumination.

Energy efficiency improves by 94.1% with light-assisted operation.

Abstract

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.