## 1 Introduction  
Electricity driven resistive heaters have been widely used in energy conversion [1; 2; 3]. As current passes through the conductive materials, inelastic collisions between accelerated electrons and phonons occur and generate heat under an applied voltage [4]. Metallic materials (e.g., copper and silver) have been commonly used as heating elements [5]. However, these heating elements have relatively high density and rigidity. Recent research has focused on using carbonaceous materials as heating elements including carbon nanotubes (CNTs), graphene, and carbon fiber [2; 6]. However, the agglomeration issues and difficulty of dispersing of CNT/graphene could lead to higher costs and time consumption during the manufacturing process. [7] Compared with other heating elements, carbon fiber is a flexible conducting material with low density and high strength [5]. Carbonaceous electrical heaters are now used in wearable heating fabric, heating equipment, defogger devices, and thermal therapy [1; 4; 8]. However, very few carbonaceous electrical heaters are used in floor or wall tiles for indoor climate control, which requires reliable mechanical properties, high thermal conductivity, and safe insulation of the surface parts.  
Ceramic is an ideal material as the surface element of electrical heaters because of its particular advantages such as low density when compared to metal, excellent chemical inertness, high thermal conductivity, reliable mechanical property, good insulation, and low cost [9]. The triaxial kaolin-feldspar-quartz is one of the most commonly used ceramic systems and widely used as earthquake, stoneware, domestic porcelain, dental porcelain, and insulators [10; 11]. The obtained final phase of ceramic is mullite, which is an excellent thermal conductive material [12]. Many researchers have studied the interface between the fiber and ceramic matrix to achieve functional ceramic composites for electromagnetic shielding applications [13; 14; 15; 16]. However, little has been reported on applying ceramics as electricity driven resistive heaters [17; 18; 19].  
In a typical fabrication process of the carbon fiber/ceramic composites, carbon fiber is produced first and then fired together with ceramic precursors in the subsequent firing process. Therefore, two firing steps were needed to produce the carbon fiber/ceramic composites. It would save significant energy and time if the carbon fiber precursor and ceramic precursor can be fired together through a single firing to obtain the carbon fiber/ceramic composites. The most commonly used precursor for carbon fiber is polyacrylamide (PAN) [20]. PAN fibers are strong and flexible, and can be more easily handled than the relatively brittle carbon fibers [21].  
Herein, we report a novel method to achieve the fabrication of carbon fiber/ceramic composites from the mixture of carbon fiber precursor PAN and ceramic precursor through a single firing process. During the firing process, the PAN carbonization and ceramic sintering were accomplished simultaneously. The mechanical properties of the carbon fiber/ceramic composite were examined. The microscopic morphologies and physical features including linear shrinkage, weight loss, bulk density, open porosity, and water absorption were characterized. The firing temperature effect on the composite performance was also investigated. Furthermore, the electro-thermal performance of the as-prepared composite was analyzed. The as-prepared carbon fiber/ceramic composite showed great potential to be used as indoor climate control heaters.