A review on the transition from conventional to bipolar designs of anode-less all-solid-state batteries

Abstract

Large-scale energy storage technologies are becoming increasingly necessary for the effective use of clean and sustainable energy sources. Solid-state lithium batteries (SSLBs) based on non- or less flammable solid-state electrolytes are gaining popularity owing to their greater safety than regular Li-ion batteries. Additionally, when built using a bipolar architecture, SSLBs can offer significant advantages in terms of battery parameters, i.e., power and energy densities together with the cost. Since the introduction of “rocking chair” batteries in the 1990s, the energy density of lithium-ion batteries has steadily increased. In order to achieve a higher energy density, an anode-free arrangement has been proposed and extensively researched in recent years. This review article briefly discusses the key elements and technologies for bipolar SSLBs, including composite electrodes, bipolar plates, and Li⁺-conducting SEs. This paper highlights the present problems and difficulties in this developing sector while providing an outline of the recent advancements in anode-free solid-state batteries. Although there are various challenges that need to be addressed, anode-free solid-state batteries can be developed faster using the knowledge gained from solid-state lithium metal batteries and liquid electrolytes. This will indeed assist the existing battery technology to move one step forward towards the development of novel, inexpensive, eco-friendly and high-performance bi-polar anode-less solid-state batteries.