Fast Li+ Transfer Scaffold Enables Stable High-Rate All-Solid-State Li Metal Batteries

Sluggish transfer kinetics caused by solid–solid contact at the lithium (Li)/solid-state electrolyte (SE) interface is an inherent drawback of all-solid-state Li metal batteries (ASSLMBs) that not only limits the cell power density but also induces uneven Li deposition as well as high levels of interfacial stress that deteriorates the internal structure and cycling stability of ASSLMBs. Herein, a fast Li+ transfer scaffold is proposed to overcome the sluggish kinetics at the Li/SE interface in ASSLMBs using an α-MnO2-decorated carbon paper (CP) structure (α-MnO2@CP). At an atomic scale, the tunnel structure of α-MnO2 exhibits a great ability to facilitate Li+ adsorption and transportation across the inter-structure of α-MnO2@CP, leading to a high critical current density of 3.95 mA cm−2 at the Li/SE interface. Meanwhile, uniform Li deposition can be guided along the skeletons of α-MnO2@CP with minimized volume expansion, significantly improving the structural stability of the Li/SE interface. Based on these advantages, the ASSLMBs using α-MnO2@CP protected the Li anode and can stably cycle up to very high charge/discharge rates of 10C/10C, paving the way for developing high-power ASSLMBs.