The transition to renewable energy is essential for sustainable development, in which advanced energy-efficient storage solutions, in particular rechargeable batteries, play a key role. Batteries are becoming increasingly important not only for electric mobility and grid balancing, but also for industrial and residential applications. However, as energy density increases, so do safety risks such as thermal runaway, which can jeopardise user confidence. The aim of this study is to examine the battery technology value chain at a systemic level, with a particular focus on the role of safety testing and technological innovation. The research identifies three main gaps in literature: the lack of value chain level integration, the under-representation of AI-based safety technologies, and the limited comparison of regional (EU, US, Asia) regulatory regimes. By examining the interrelationships between material selection (cathode, anode), cell design, testing protocols and regulatory environment, the study highlights the complex challenges and development directions for battery energy storage. The study reviewed global industry trends and critically assessed forecasts and analyses from international consultancies such as Ernst & Young (EY). These concluded that thorough testing of lithium-ion batteries is key to ensuring long-term reliability, safety and performance by reducing operational risks and increasing product efficiency. Advanced testing infrastructure not only serves quality control and regulatory compliance, but also makes a fundamental contribution to increasing energy efficiency and supporting the green transition. For Europe in particular, it is of paramount importance to expand testing capacities to enable the continent to take a leading role in the safe and sustainable development of batteries.

Supercritical carbon dioxide (scCO2) is a non-toxic, inert, and widely used solvent in green chemistry, offering tunable properties such as density, diffusivity, viscosity, and polarity, adjustable through temperature, pressure, or co-solvent addition. This study employs the Design of Experiment (DoE) methodology to optimize scCO2-assisted synthesis of Li-S battery cathodes, presenting the first systematic investigation of how scCO2 conditions affect the structural and surface properties of reduced graphene oxide (rGO) during sulfur decoration. Results show that temperature and pressure significantly influence sulfur integration and cathode performance. By combining DoE with detailed electrochemical impedance analysis using complex nonlinear least squares fitting, the study provides deeper insight into composite electrochemical behavior under varying conditions. An optimal rGO structure with low charge transfer resistance, enabling efficient ion and electron transport, was obtained at 150 bar and 60 °C, balancing sulfur loading and pore accessibility. Conversely, harsher conditions (180 bar, 80 °C) caused sulfur agglomeration and higher resistance, reducing performance. These findings highlight the necessity of precisely controlling scCO2 synthesis parameters to enhance cathode structure and improve electrochemical performance and long-term stability of Li-S batteries.