# Energy Storage in Carbon Fiber-Based Batteries: Trends and Future Perspectives
## 3 Results and Discussion
### Document Analysis
The thematic evolution of the topic is presented in Figure 14 in five time periods. The first time period (2013-2015) reveals that the focus was primarily on \"anode\", \"carbon fibres\", \"energy storage\", and \"mechanical properties\". These themes indicate an early emphasis on understanding and improving the fundamental components and properties of energy storage systems. As we move to the second time period (2016-2017), the themes evolve to include \"cathodes\", \"carbon fibres\" and \"energy efficiency\", reflecting a shift towards optimizing both the anode and cathode materials and improving the overall efficiency of energy storage devices. In the third time period (2018-2019), the focus expands to \"carbon fibres\", \"anodes\", and \"composite materials\" suggesting advancements in integrating carbon fibres into composite materials to enhance the performance and durability of batteries. The fourth time period (2020-2021) shows a continued emphasis on \"carbon fibres\", \"anodes\", and \"energy storage\" indicating ongoing research into improving these critical components. Additionally, \"structural batteries\" and \"carbon nanofibers\" emerge as significant themes, highlighting innovations in battery design and materials. Finally, in the  
Figure 12: Conceptual structure map. fifth time period (2022-2023), the themes include \"carbon fibres,\" \"anodes\", and \"lithium-ion batteries,\" demonstrating a mature focus on integrating carbon fibres into lithium-ion batteries to enhance their performance. The emergence of \"energy efficiency\" and \"structural batteries\" as consistent themes throughout the periods underscores the importance of these areas in the ongoing development of advanced energy storage solutions. Considering the bibliometric analyses of the paper, Figure 15 presents key trends and future perspectives in energy storage technologies based on carbon fiber-based batteries. The bibliometric analysis highlights three primary areas: the development of carbon fiber-based anodes for lithium-ion batteries, advancements in next-generation carbon fiber-based cathodes, and progress in solid electrolytes. Each domain faces significant challenges, such as dendrite formation and volume expansion in anodes, as well as the urgent need for cobalt-free alternatives in cathodes due to the high costs and extraction difficulties associated with cobalt. Efforts in solid electrolytes focus on balancing high ionic conductivity with strong mechanical properties to ensure the multifunctionality of these composite materials. Moreover, gel-based electrolytes, due to their semi-solid nature, help to reduce electrode polarization and maintain stable performance under high charge/discharge rates, making them highly suitable for demanding energy storage applications. Additionally, the geographical distribution of research contributions, with  
Figure 14: Thematic evolution of the topic. Figure 13: Thematic map of the topic. leading countries showing high citation impacts, although international collaboration remains limited. This suggests that while some nations dominate high-impact research, global collaboration needs to be strengthened to accelerate progress in this field.