Reducing the Interfacial Resistance in All‐Solid‐State Lithium Batteries Based on Oxide Ceramic Electrolytes

Abstract

All‐solid‐state lithium batteries (ASSLBs) are regarded as next‐generation advanced energy‐storage devices, owing to their high energy density and safety. The interfacial resistance is a crucial factor affecting the practical application of ASSLBs. ASSLBs based on oxide‐based ceramic electrolytes (OCEs) still exhibit poor electrochemical performance, owing to the large interfacial resistance. Area‐specific resistance values at the interfaces ranging from thousands of ohms to several ohms per square centimeter have been achieved using multiple strategies. This Review summarizes multiple existing advanced strategies used to reduce the interfacial resistance between OCEs and electrodes through interfacial engineering. We also propose some perspectives for the future development of ASSLBs based on OCEs.

Tape‐Casting Li0.34La0.56TiO3 Ceramic Electrolyte Films Permit High Energy Density of Lithium‐Metal Batteries

“…Li 7 La 3 Zr 2 O 12 (LLZO), Li 0.34 La 0.56 TiO 3 (LLTO), Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP), and Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 (LATP) are outstanding oxide electrolytes in solid‐state electrolytes due to their excellent thermostability, wide electrochemical stable windows, superior Li‐ionic conductivity, high elastic modulus, low cost, and environmental friendliness . In recent years, these oxide electrolytes have exhibited an improved performance with the decrease of interfacial resistance in ASSLBs . The ASSLBs based on oxide electrolytes have already exhibited a comparable discharge capacity with traditional Li‐ion battery .…”

Scalable Processing Routes for the Production of All‐Solid‐State Batteries—Modeling Interdependencies of Product and Process

“…[ 31–33 ] Concerning processing of different SES materials, challenges arise indicating the complexity of the production system. Although the thermal and chemical properties of oxides are of great advantage for the application in ASSBs, [ 34 ] drawbacks are evident due to their high interfacial [ 35 ] and grain boundary resistances, [ 36 ] which reduce the ionic conductivities. [ 37 ] Therefore, a complex sintering step at high temperatures (Li 7 La 3 Zr 2 O 12 (LLZ) ≈1100 °C; Li 1+ x Al x Ti 2− x (PO 4 ) 3 (LATP) and Li 1+ x AL x Ge 2− x (PO 4 ) 3 (LAGP) ≈800 °C.…”

“…[31][32][33] Concerning processing of different SES materials, challenges arise indicating the complexity of the production system. Although the thermal and chemical properties of oxides are of great advantage for the application in ASSBs, [34] drawbacks are evident due to their high interfacial [35] and grain boundary resistances, [36] which reduce the ionic conductivities. [37] Therefore, a complex sintering step at high temperatures (Li 7 La 3 Zr 2 O 12 (LLZ) %1100 C; Li 1þx Al x Ti 2Àx (PO 4 ) 3 (LATP) and Li 1þx AL x Ge 2Àx (PO 4 ) 3 (LAGP) %800 C. [38] A reduced sintering temperature for LLZ can be achieved by adding additives, e.g., Al 2 O 3 [39] ), which implicates difficulties and high costs in scaling up, is required to densify the oxide layers and increase ion conductivity.…”

“…[49] As few sulfide SES are stable against lithium metal, protective layer such as polymers or LiPON are used to stabilize the interface. [35,50] The main disadvantage for the use of sulfidic materials in production is the instability toward water in an atmospheric environment, where H 2 S, a toxic gas, is easily formed. [51,52] For this reason, processing must take place in a dry room or inert gas atmosphere.…”

Bifunctional In Situ Polymerized Interface for Stable LAGP‐Based Lithium Metal Batteries

“…Adopting a buffer layer between Li metal anode and SSEs is deemed to be an effective strategy to solve the aforementioned problems. [25,26] Until now, much effort has been dedicated to designing various buffer layers, such as 3D polymer-gel layers, [27] poly(oxyethylene) (PEO) buffer layer, [16] Al 2 O 3 nanolayer, [28,29] and germanium (Ge) thin film. [14] Nevertheless, due to the poor elastic feature of solid inorganic buffer layers, the formed interface at the buffer layers and the LAGP SSEs can be severely damaged by the volume change of the anode during the repeated Li plating/stripping processes, leading to a rapidly increased interfacial resistance.…”