A Flexible Self‐Regulating Heating Material With Enhanced Cycling Stability

ABSTRACT This work proposes a novel strategy for developing a flexible self‐regulating heating material with enhanced cycling stability. The approach involves incorporating two types of carbon black (CB) fillers with different conductivities, together with nanoscale silica, into a polydimethylsiloxane (PDMS) matrix. The addition of nanoscale silica significantly improves the dispersion and interconnectivity of CB fillers, thereby promoting the formation of a conductive network. Meanwhile, its strong interfacial interaction with the matrix helps maintain the integrity of the conductive network during electric heating cycling, leading to enhanced stability of room temperature resistance and positive temperature coefficient (PTC) reproducibility. The optimized composite containing 2.3 wt% silica exhibited a room‐temperature resistivity one order of magnitude lower than that of the composite without silica, while maintaining high resistance stability (Δ R / R 0 < 5%) and a PTC intensity exceeding three orders of magnitude after 600 on–off cycles. The synergistic effect of the binary CB and silica in the PDMS matrix offers a cost‐effective approach for fabricating flexible self‐regulating heating materials with exceptional long‐term stability and aging resistance, making them highly promising for intelligent heating applications.