LIGNOCAP · Lignin-derived carbon fiber flexible supercapacitors

Lignin-derived carbon fiber flexible supercapacitors

i. Lignin-Derived Carbon Fiber Flexible Supercapacitors [LIGNOCAP] Compared to supercapacitors (SCs), research on flexible supercapacitors (FSCs) are still in its infancy due to their high cost, low energy density, low capacitance, poor flexibility, safety problems, leakage, toxicity and scarcity of some nanomaterials, and poor cycling stability, which continuously force us to search for alternative sustainable and high-performance electrode materials. To overcome these obstacles, clearer coalitions between fiber thickness and modulated structure, porosity, functionality, effect of dopant, electrochemical performance and cyclability are needed. We have correlated the physical properties of carbon fiber composite, with their electrochemical properties by using a combination of synthetic approaches and in depth characterization studies. These insights will provide a great support for the design of the next generation advanced FSCs and will accelerate their commercialization. ii. Na-ion Batteries Similarly, to overcome the challenges of lithium (Li) batteries like less availability of Li resources, sodium (Na) batteries based on the abundant Na resources have gradually become a promising alternative to Li batteries. Among numerous anode materials, metallic sodium (Na) has been widely regarded as the ultimate anode material for next-generation Na batteries on account of its ultra-high theoretical capacity of 1166 mAh g-1 and a lowest negative electrochemical potential (Na+/Na = −2.714 V vs standard hydrogen electrode (SHE)). However, metallic sodium deposition is considered to be quite random process, resulting in severe sodium dendrite formation during cycling. Several studies have employed carbon fabrics as a functional skeleton to guide the metallic deposition based on uniform nucleation at the very first cycle. Most studies have claimed that the porosity would benefit the metallic deposition behaviour, but in fact, the specific effect of defective structures in carbon matrix haven’t been carefully considered, whose functions definitely differ from those of the pore structures. It has never been clearly proven whether the defect or pore is indeed affecting the metallic deposition as well as entire electrochemical performance because most porous carbon materials possess defective structures at the same time. Objectives: The goal is to accelerate the commercialization of our high performance flexible supercapacitors (FSCs) by interacting closely with the energy conversion/storage industry. We also carried out an additional research on Na-ion batteries by using our as-prepared carbon fibers from lignin. The electrospinning allows producing the desirable carbon fibers with interesting features of structure, porosity, thickness and morphology. Also, we have investigated the synthesis of various carbon fibers not only from Lignin, but also from biomass. HTC carbon spheres were also synthesized from fructose to incorporate the Fe NPs and encapsulate within the carbon fibers to enhance the stability of Fe NPs. • Materials Synthesis and Characterization of CFC • Electrochemical evaluation • Results and Exploitation

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