Sodium carboxymethylcellulose-based aerogel as friction positive layer material for high-performance triboelectric nanogenerator

Cellulose and its derivatives are biopolymers abundant in nature, with the advantages of low cost, biodegradability, and high positive friction polarity. In this paper, a novel friction positive layer material sodium carboxymethyl cellulose (CMC)-epichlorohydrin (ECH)-polyethyleneimine (PEI) aerogel (CEP aerogel) and polytetrafluoroethylene (PTFE) film are reported as a friction pair to prepare high-performance CEP aerogel based triboelectric nanogenerator (CEP-TENG) for mechanical energy harvesting and sensing fields. The systematic optimization of the preparation process of CEP aerogel to improve its friction positive polarity not only expands the field of friction positive layer materials but also facilitates its better application to TENG with excellent output performance. The corresponding CEP-TENG can produce open-circuit voltage of 203 V, short-current density of 8.2 µA/cm 2 , and a power density of 3.38 W/m 2 under the applied force of 15 N and frequency of 4 Hz, which is 13.5 times and 27.3 times higher than that of CMC aerogel and 0.03 mm PTFE film. In addition, CEP aerogel-based TENGs have been proven to be effective in powering electronic devices by charging commercial capacitors and detecting human motion such as finger tapping and arm bends. Therefore, the investigation demonstrates the feasibility of CEP aerogel as a friction layer material, thus providing insights to promote low cost-effective and environmentally friendly TENG development.