Activated carbon materials are prepared from phenolic resin precursors by physical activation to fabricate electrodes for electric double-layer capacitors (EDLCs). Pore size and surface area of the carbon materials are controlled during the synthesizing process and after the carbonization through activation in a CO₂ atmosphere to different levels of burn-off. The resultant carbon materials were evaluated as EDLC electrodes, using electrochemical impedance spectroscopy (EIS) and galvanostatic charge–discharge (GCD) measurements with the organic electrolyte of spiro-(1,1′)-bipyrrolidinium tetrafluoroborate in propylene carbonate, SBPBF₄/PC. The results of the study showed that the capacitance of carbon materials, as well as energy density of the EDLC cells, increased by increasing the level of burn-off (activation). The 46% activated carbon gave a capacitance of ∼160 F g⁻¹ and an energy density of ∼35 W h kg⁻¹, at a current density of 1 mA cm⁻². The long term cycling tests showed high cycling stability of these carbon materials.

Batteries that extend performance beyond the intrinsic limits of Li-ion batteries are among the most important developments required to continue the revolution promised by electrochemical devices. Of these next-generation batteries, lithium sulfur (Li–S) chemistry is among the most commercially mature, with cells offering a substantial increase in gravimetric energy density, reduced costs and improved safety prospects. However, there remain outstanding issues to advance the commercial prospects of the technology and benefit from the economies of scale felt by Li-ion cells, including improving both the rate performance and longevity of cells. To address these challenges, the Faraday Institution, the UK’s independent institute for electrochemical energy storage science and technology, launched the Lithium Sulfur Technology Accelerator (LiSTAR) programme in October 2019. This Roadmap, authored by researchers and partners of the LiSTAR programme, is intended to highlight the outstanding issues that must be addressed and provide an insight into the pathways towards solving them adopted by the LiSTAR consortium. In compiling this Roadmap we hope to aid the development of the wider Li–S research community, providing a guide for academia, industry, government and funding agencies in this important and rapidly developing research space.