All-solid-state hybrid electrode configuration for high-performance all-solid-state batteries: Comparative study with composite electrode and diffusion-dependent electrode

• Published in: Journal of power sources Vol. 518; p. 230736
• Main Authors: Kim, Ju Young, Jung, Seungwon, Kang, Seok Hun, Lee, Myeong Ju, Jin, Dahee, Shin, Dong Ok, Lee, Young-Gi, Lee, Yong Min
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.01.2022
• Subjects: All-solid-state battery; Electrode design; Hybrid structure; Lithium-ion transport; All-solid-state battery; Hybrid structure; Electrode design; Lithium-ion transport
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2021.230736

To realize high-performance all-solid-state batteries, an efficient design for all-solid-state electrodes is vital. Composite electrode, which is comprised of well-mixed active material and solid electrolyte, is a typical structure to build well-percolated ionic pathways within the electrode. In contrast, diffusion-dependent electrode, which consists mostly of active material, is an emerging approach that utilizes interparticle diffusion between active material particles for charge/discharge. This design enables maximization of energy density and simplification of the fabrication process. Herein, we present a hybrid all-solid-state electrode that combines the merits of each electrode as a new electrode concept. This electrode consists of a bilayer structure of the composite electrode and the diffusion-dependent electrode, and its electrochemical features such as initial Coulombic efficiency, capacity retention, and energy density are systematically analyzed. Owing to the active utilization of lithium-ion transports via percolated solid electrolyte particles and interparticle diffusion of active material particles, the graphite-based hybrid electrode with a practically meaningful capacity (∼4 mA h cm−2) is demonstrated to deliver moderately high energy densities at various C-rates. In particular, silicon/graphite-based hybrid electrode can exhibit high normalized capacities of 5.83 mA h cm−2 and 1300 mA h cm−3, which are among the highest values reported to date for all-solid-state batteries. [Display omitted] •Hybrid electrode design is proposed as a high-performance all-solid-state electrode.•This electrode utilizes lithium-ion conduction and diffusion for charge/discharge.•The silicon/graphite-based hybrid electrode realizes excellent energy density.