# Energy Storage in Carbon Fiber-Based Batteries: Trends and Future Perspectives
## 3 Results and Discussion
### Document Analysis  
Table 8 presents the most impactful documents based on the global citations they have received. Based on the results, the studies of [PERSON]. [PERSON] et al. (2018), [PERSON] et al. (2013), [PERSON] et al. (2014), [PERSON] et al. (2018), and [PERSON] et al. (2018) emerged as the top-5 most impactful ones. Taking these outcomes into account, it can be inferred that the focus is on developing high-performance, durable electrochemical anodes by exploring various coatings on carbon fiber that incorporate nanoparticles and lithium. This is because the practical use of non-coated lithium metal anodes has been limited by challenges such as low cycling efficiency, short lifespan, and safety concerns. To better understand the scope and breadth of the topic and how it has been shaped throughout the years, keywords plus were used to further analyze the documents. Specifically, keywords plus result in more accurate and representative outcomes when compared to author's keywords ([PERSON] et al., 2016) and therefore, have been used in the analysis. Among the keywords plus used, \"carbon fibers\" (n = 560), \"anodes\" (n = 317), \"lithium-ion batteries\" (n = 288), \"electrodes\" (n = 179), and \"lithium compounds\" (n = 177) emerged as the top-5 most commonly used. Figure 8 summarizes the top-10 most frequently used keywords plus. Based on the outcomes, the scientific community has focused on three main areas. Firstly, the most investigated is the development of anodes for lithium-ion batteries, as this area faces high global demand and presents greater challenges compared to cathodes. Anodes are subject to issues such as dendrite formation during charging ([PERSON] et al., 2016), significant volume changes of lithium during charge and discharge, leading to crack formation ([PERSON] et al., 2016), and potential side reactions with the electrolyte, which generate products that can degrade battery performance and reduce capacity ([PERSON] et al., 2016). Secondly, the development of a new generation of carbon fiber-based cathodes involves activating them with coatings of LiFePO\({}_{4}\), LiCoO\({}_{2}\), or their derivatives. Additionally, recent efforts have focused on developing cobalt-free cathodes due to the high cost and difficulty of extraction. These cobalt-free \begin{table}
\begin{tabular}{c c c} \hline
**Country** & **TC** & **Average Document Citations** \\ \hline Georgia & 270 & 90 \\ Czech Republic & 88 & 88 \\ Singapore & 897 & 74.8 \\ Hong Kong & 779 & 55.6 \\ Australia & 1408 & 45.4 \\ United States & 2963 & 42.3 \\ China & 20,033 & 38.7 \\ Switzerland & 37 & 37 \\ Turkey & 37 & 37 \\ Thailand & 173 & 34.6 \\ \hline \end{tabular}
\end{table} 
Table 7: Countries that with the highest average citations received per document. \begin{table}
\begin{tabular}{c c c c} \hline
**Document** & **Total Citations** & **Total Citations per Year** & **Normalized Total Citations** \\ \hline R. [PERSON] et al. (2018) ([PERSON] et al., 2018) & 622 & 88.86 & 9.12 \\ [PERSON] et al. (2013) ([PERSON] et al., 2018) & 598 & 49.83 & 5.46 \\ [PERSON] et al. (2014) ([PERSON] et al., 2018) & 536 & 48.73 & 5.62 \\ [PERSON]. [PERSON] et al. (2018) ([PERSON] et al., 2018) ([PERSON] et al., 2018) & 462 & 66 & 6.78 \\ [PERSON] et al. (2018) ([PERSON] et al., 201 alternatives offer more sustainable solutions for large-scale production while maintaining comparable performance metrics [63; 64]. The final area of focus is the development of solid electrolytes, which must simultaneously achieve high ionic conductivity and elevated mechanical properties to guarantee the multifunctionality of the composite. However, it has been demonstrated that these two properties are often in conflict [18; 65]. The keyword co-occurrence network presented in Figure 9 revealed three main areas. Specifically, the central and most prominent cluster is focused on 'carbon fibers', which is heavily linked to \"lithium-ion batteries\" and \"anodes\".