Defect reduction to enhance the mechanical strength of nanocellulose carbon aerogel

Carbon aerogels prepared from renewable nano building blocks are rising-star materials and hold great promise in many fields. However, various defects formed during carbonization at high temperature disfavor the stress transfer and thus the fabrication of flexible carbon aerogel from renewable nano building blocks. Herein, a structural defect-reducing strategy is proposed by altering the pyrolysis route of cellulose nanofiber. Inorganic salt that inhibits the generation of tar volatilization during pyrolysis can prevent the formation of various structural defects. Microstructure with fewer defects can reduce stress concentration and remarkably enhance the compressibility of carbon aerogel, thus increasing the maximum stress retention of carbon aerogel. The carbon aerogel also has high stress sensor sensitivity and excellent temperature coefficient of resistance. The structural defect-reducing strategy will pave a new way to fabricate high-strength carbon materials for various fields.