In situ generation of 3D graphene-like networks from cellulose nanofibres in sintered ceramics

Abstract

Establishing a 3D electrically percolating network in an insulating matrix is key to numerous engineering and functional applications. To this end, using hydrophobic carbon nanofillers is tempting, but still results in suboptimal performance due to processing challenges. Here, we demonstrate how natural cellulose nanofibres can be in situ transformed into graphene-like sheets connected to a 3D network enhancing both the transport and the mechanical properties of sintered engineering ceramics. The network architecture also permits the decoupling of electrical and thermal conductivities, which represents a major obstacle in attaining efficient thermoelectric materials. We foresee that our transferable methodology can pave the way for the use of natural nanofibres to unravel the full potential of 3D graphene-like networks to accelerate development in fields like energy and telecommunications.

Advanced Cellulose–Nanocarbon Composite Films for High-Performance Triboelectric and Piezoelectric Nanogenerators

“…This confines the fillers to fewer but thicker conduction paths at the same filler content. Similar effects have been observed for electrical percolation in fine- and coarse-grained ceramics [ 51 , 52 ].…”

Researches for higher electrical conductivity copper‐based materials

“…The preparation of network-structured composite materials has been realised in the fields of polymers 90,91 and ceramics. 92,93 Because CNTs/Gr forms connected pathways in the matrix, the composite material has excellent electrical conductivity, thermal conductivity and mechanical properties. Cao et al 94 embedded graphene in copper through elaborate interface design and morphology control and realised high electron mobility and high electron density simultaneously in copper.…”

Controllable fabrication and multifunctional applications of graphene/ceramic composites

“…As described in Sections 3.2 and 3.3, the addition of graphene can cause great changes in both electrical conductivity and thermal conductivity of the composites, but the variations may be quite different in the same composites. For example, Kocjan et al [135] discovered electric and thermal decoupling in the YSZ composites with the graphene-like network. Due to a highly electrically conductive network, the electrical conductivity of the composites was improved by 14 orders of magnitude, whereas the thermal conductivity only increased by 6% because of the strong interfacial thermal resistance, which shows the potential of thermoelectricity improvement.…”