High-Power Bipolar Solid-State Batteries Enabled by In-Situ-Formed Ionogels for Vehicle Applications.

Employing solid electrolytes (SEs) for lithium-ion batteries can boost the battery tolerance under abusive conditions and enable the implementation of bipolar cell stacking, leading to higher cell energy and power density as well as simplified thermal management. In this context, a bipolar solid-state battery (SSB) has received ever-increasing attention in recent years. However, poor solid-solid interfacial contact within the bipolar SSB deteriorates the battery power capability, representing a technical challenge for vehicle applications. In this work, a bipolar SSB pouch cell with two cell units connected in series is demonstrated without any short circuit or current leakage. With the assistance of an in-situ-formed nonflammable ionogel at particle-to-particle interfaces, the constructed bipolar cell manifests superior power capability and can meet the engineering cold crank requirements in 0, -10, and -18 °C environments. Furthermore, the excellent tolerance of the ionogel-introduced bipolar SSB under abusive conditions was proved by folding, cutting, and burning the cells. The above salient features suggested that the developed strategy herein holds promise to advance the next-generation high-performance SSBs.

Passivation of the Cathode-Electrolyte Interface for 5 V-Class All-Solid-State Batteries.

An all-solid-state battery is a potentially superior alternative to a state-of-the-art lithium-ion battery owing to its merits in abuse tolerance, packaging, energy density, and operable temperature ranges. In this work, a 5 V-class spinel LiNi0.5Mn1.5O4 (LNMO) cathode is targeted to combine with a high-ionic-conductivity Li6PS5Cl (LPSCl) solid electrolyte for developing high-performance all-solid-state batteries. Aiming to passivate and stabilize the LNMO-LPSCl interface and suppress the unfavorable side reactions such as the continuous chemical/electrochemical decomposition of the solid electrolyte, oxide materials including LiNbO3, Li3PO4, and Li4Ti5O12 are rationally applied to decorate the surface of pristine LNMO particles with various amounts through a wet-chemistry approach. Electrochemical characterization demonstrates that the composite cathode consisting of 8 wt % LiNbO3-coated LNMO and LPSCl in a weight ratio of 70:30 delivers the best electrochemical performance with an initial discharge capacity of 115 mA h g-1 and a reversible discharge capacity of 80 mA h g-1 at the 20th cycle, suggesting that interfacial passivation is an effective strategy to ensure the operation of 5 V-class all-solid-state batteries.