# Energy Storage in Carbon Fiber-Based Batteries: Trends and Future Perspectives
###### Abstract  
Carbon fiber-based batteries, integrating energy storage with structural functionality, are emerging as a key innovation in the transition toward energy sustainability. Offering significant potential for lighter and more efficient designs, these advanced battery systems are increasingly gaining ground. Through a bibliometric analysis of scientific literature, the study identifies three primary research areas: (i) the development of anodes for lithium-ion batteries, tackling challenges such as dendrite formation and performance degradation; (ii) the creation of new carbon fiber-based cathodes with coatings of LiFePO\({}_{4}\), LiCoO\({}_{2}\), or other nanoparticles, alongside efforts to develop cobalt-free alternatives; and (iii) the advancement of solid electrolytes that achieve a balance between ionic conductivity and mechanical strength. These advancements position carbon fiber-based batteries as promising solutions for seamless integration into various structural applications. The analysis of publication trends, citation patterns, and collaboration networks provides critical insights into the ongoing technological developments, current research challenges, and emerging trends in this field. Moreover, the study highlights potential research directions, underscoring the importance of continuous innovation to fully realize the potential of carbon fiber-based energy storage technologies. b +
Footnote †: journal: Applied sciences  
The general architecture of carbon fiber-based batteries is illustrated in Figure 1. It consists of a carbon fiber-reinforced polymer composite, where the carbon fibers serve as both the anode (negative electrode) and the cathode (positive electrode) [15; 16]. A separate interlayer or fiberglass functions as the separator, ensuring that the electrodes do not short-circuit [17]. The entire structure is embedded within a solid electrolyte, which could be a polyelectrolyte, polymer-based electrolyte, or ceramic electrolyte, depending on the specific design and performance requirements [18; 19]. Here, solid electrolytes can function effectively as separators. These systems leverage the unique properties of solid electrolytes, which not only facilitate ion transport between the anode and cathode but also serve as a physical barrier. The dual functionality of solid electrolytes enhances the overall safety and performance of the battery, making them an attractive option in the development of advanced energy storage solutions [20]. Electrode polarization is a key factor in the performance of carbon fiber-based batteries, affecting charge/discharge rates, energy efficiency, and lifespan [21; 22]. It is influenced by internal resistance, electrode surface characteristics, and electrolyte composition. In carbon fiber systems, factors like fiber structure, porosity, and coatings impact ion transfer and reaction kinetics. Additionally, the choice of electrolyte, especially solid-state or polymer-based, can alter polarization levels. Mitigating polarization involves optimizing electrode design and choosing electrolytes that enhance ionic conductivity, leading to more efficient energy storage and longer battery life. This understanding is crucial for advancing carbon fiber-based batteries. The scientific community has been particularly focused on leveraging the high surface area, tunable porosity, and excellent electrochemical stability of coated carbon fibers to improve the performance of batteries. One of the most significant advantages of carbon fiber-based electrodes is their potential to enhance charge/discharge rates, increase energy density, and extend the lifespan of batteries [23]. Moreover, the inherent flexibility and durability of carbon fibers open new possibilities for the development of flexible and wearable energy storage devices, which are increasingly in demand in consumer electronics and biomedical applications.