The recent advances of the lithium-ion battery concept towards the development of sustainable energy storage systems are herein presented. The study reports on new lithium-ion cells, developed over the last few years with the aim of improving the performance and sustainability of the electrochemical energy storage. Alternative chemistries, involving anode, cathode and electrolyte components, are herein recalled in order to provide an overview of state of the art lithium-ion battery systems, with particular care on the cell configurations currently proposed at the laboratory-scale level. Hence, the review highlights the main issues related to full cell assembly, which have been tentatively addressed by limited number of reports, while many recent papers describe material investigation in half-cells, i.e., employing lithium metal anode. The new battery prototypes here described are evaluated in terms of electrochemical performances, cell balance, efficiency and cycling life. Finally, the applicability of these suitable energy storage systems is evaluated in the light of their most promising characteristics, thus outlining a conceivable scenario of new generation, sustainable lithium-ion batteries.

We report a comparative study of the electrochemical lithium diffusion properties within the olivine structure of LiMn 0.5 Fe 0.5 PO 4 , LiFePO 4 and LiMnPO 4 materials prepared by solvothermal pathway.The study includes careful analysis performed by potentiodynamic cycling with galvanostatic acceleration (PCGA), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic intermittent titration technique (GITT), carried out in order to investigate the features of the Fe 3+ /Fe 2+ and Mn 3+ /Mn 2+ redox processes and the lithium ion transport within the olivine structure. The electrochemical investigation reveals a shift of the redox potential of Fe 3+ /Fe 2+ and Mn 3+ /Mn 2+ couples toward higher and lower values, respectively, in LiMn 0.5 Fe 0.5 PO 4 in respect to the bare materials. Interestingly, the study reveals lithium diffusion coefficients depending on the state of the charge of the materials as well as on the adopted technique. Accordingly, CV leads to lithium diffusion coefficient of the order of 10 −12 cm 2 s −1 for LiMnPO 4 , 10 −9 cm 2 s −1 for LiFePO 4 and 10 −11 cm 2 s −1 for LiMn 0.5 Fe 0.5 PO 4 . EIS mainly indicates lower value of lithium diffusion coefficient, i.e. 10 −13 cm 2 s −1 for LiMnPO 4 , 10 −12 for LiFePO 4 and 10 −13 cm 2 s −1 for LiMn 0.5 Fe 0.5 PO 4 . GITT provides a wide range of Li + diffusion coefficient, depending on the Li 1-x MePO 4 stoichiometry, that is, 10 −14 -10 −10 cm 2 s −1 for LiMnPO 4 and LiFePO 4 , and 10 −13 -10 −10 cm 2 s −1 for LiMn 0.5 Fe 0.5 PO 4 . The wide diffusion coefficient window obtained by changing the state of charge and the adopted technique, sheds light on the complex trend of the lithium diffusion in olivines and indicates that the adopted technique may actually influence the materials evaluation.

The historical development of lithium metal batteries is briefly introduced.• General strategies for protection of Li metal anodes are reviewed. • Specific challenges of ASSBs, Li-S and Li-air batteries are extensively discussed.• Current development status is reviewed and compared to the EU SET Plan targets.

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.