2020 roadmap on solid-state batteries

Abstract

Li-ion batteries have revolutionized the portable electronics industry and empowered the electric vehicle (EV) revolution. Unfortunately, traditional Li-ion chemistry is approaching its physicochemical limit. The demand for higher density (longer range), high power (fast charging), and safer EVs has recently created a resurgence of interest in solid state batteries (SSB). Historically, research has focused on improving the ionic conductivity of solid electrolytes, yet ceramic solids now deliver sufficient ionic conductivity. The barriers lie within the interfaces between the electrolyte and the two electrodes, in the mechanical properties throughout the device, and in processing scalability. In 2017 the Faraday Institution, the UK’s independent institute for electrochemical energy storage research, launched the SOLBAT (solid-state lithium metal anode battery) project, aimed at understanding the fundamental science underpinning the problems of SSBs, and recognising that the paucity of such understanding is the major barrier to progress. The purpose of this Roadmap is to present an overview of the fundamental challenges impeding the development of SSBs, the advances in science and technology necessary to understand the underlying science, and the multidisciplinary approach being taken by SOLBAT researchers in facing these challenges. It is our hope that this Roadmap will guide academia, industry, and funding agencies towards the further development of these batteries in the future.

Beyond the State of the Art of Electric Vehicles: A Fact-Based Paper of the Current and Prospective Electric Vehicle Technologies

“…The voltage losses, due to concentration polarisation, occurring in liquid electrolytes at high power applications is eliminated in solid electrolytes allowing them to use thicker electrolytes high energy density values. It's also worth to mention that solid electrolytes show outstanding resistance on dendrite propagation which enables using the advantages of Li metal as an anode [43].…”

“…Besides, there is a difference between critical current densities during charging and discharging. Today, critical current densities during charging are found to be higher than during discharging [43].…”

“…It was found out that polymer-based solid electrolytes, despite their lower ionic conductivity when compared to ceramic counterparts, shows enhanced Li wetting. Accordingly, Li wetting problem can be solved by using polymer/ceramic composites as electrolytes [43].…”

“…Besides, there is a difference between plating (charging) and stripping (discharging), and the critical current density needs to be eliminated. The mechanism and possible solutions for that are still unclear, but special attention has been paid on producing the electrolytes as dense as possible, since the dendrite propagation is drastically inhibited in dense microstructures [43].…”

Designing Spinel Li4Ti5O12 Electrode as Anode Material for Poly(ethylene)oxide-Based Solid-State Batteries

“…Within the race towards high-voltage and high-energy density active materials [ 2 ], liquid organic electrolytes result in electrochemical stability issues along with safety concerns due to their high volatility and flammability. The replacement of the liquid organic electrolyte in conventional LIBs by solid electrolytes, considered as a solution to high-capacity lithium-metal anodes owing to their mechanical strength, in solid-state batteries (SSBs), offers outstanding high-energy and high-power densities as well as inherent safety [ 3 , 4 , 5 , 6 ]. However, far from being a reality, there are still many challenges to overcome on the use of lithium metal anodes for solid-state batteries [ 7 , 8 ]: most of the solid inorganic Li ion conductors are thermodynamically unstable [ 9 ] and dendrite growth is still a problem due to the inhomogeneous dissolution and subsequent deposition over cycling [ 8 , 10 , 11 , 12 ].…”