Highly Cyclable All‐Solid‐State Battery with Deposition‐Type Lithium Metal Anode Based on Thin Carbon Black Layer

Abstract

A thin carbon black (CB) layer on a metal current collector is used as a substrate of a deposition‐type Li metal anode for a sulfide‐based all‐solid‐state battery (ASSB). In this ASSB, the capacity of the CB layer is set to ≈5–10% of the cathode. Therefore, the anode soon overcharges and a large proportion of the Li ions precipitate as Li metal on the anode during the charging process, thus this precipitated Li works as a Li metal anode. This CB‐based anode effectively suppresses short circuit of the cell, and an ASSB with this anode has shown an excellent cycle property of over 150 cycles with good capacity retention. From measurements involving cross‐sectional scanning electron microscopy, deposited Li metal layer at the CB/Ni interface is observed. It is also found that the addition of metal particles in the CB‐based anode drastically improves cell performance by extending the cycle life. An ASSB with an Ag/CB‐based anode is operated over 700 cycles at 3 mA cm−2 current density (0.5 C) with a capacity retention of ≈86% after 700 cycles.

High Performance Lithium Metal Anode with a Nanolayer of LiZn Alloy for All‐Solid‐State Batteries

“…The lithium electrode is homogenously composed of Al, which is initially present as doping metal. In addition, it was found that the Zn metal migrates into the bulk Li anode during cycling that is consistent with observations made by Samsung [73,74] . In order to increase the durability of the batteries at 1C, future works will focus on the fabrication of more stable and thicker metal layers to keep a kind of buffer alloy layer permitting fast Li + ion transport and uniform Li electrodeposition.…”

“…Finally, it was found that Zn metal migrates into the bulk Li anode during cycling that is consistent with the observations made by Samsung. [73,74] In addition, AlZn nanoparticles were also formed during the cycling coming from a reaction between Zn nanoparticles and Al initially presents in the lithium foil.…”

“…In addition, it was found that the Zn metal migrates into the bulk Li anode during cycling that is consistent with observations made by Samsung. [73,74] In order to increase the durability of the batteries at 1C, future works will focus on the fabrication of more stable and thicker metal layers to keep a kind of buffer alloy layer permitting fast Li + ion transport and uniform Li electrodeposition. The EDX spectrum 2 was acquired on a region with an unidentified particle visible inside the orange square of Figure 7(a).…”

Toward High Rate Performance Solid‐State Batteries

“…[ 139 ] The same group reported a follow‐up study using the overcharge‐type anode materials with CB in Li‐free ASSBs. [ 140 ] The anode capacity was set to be 5–10% lower than that of the cathode, so Li could be precipitated in the metal form during charging due to the absence of sufficient host materials for Li accommodation. In this study, it was explained that the CB layer becomes oversaturated due to the large overpotentials at the initial charging stage, and Li is precipitated through pores within the CB layer.…”

Clarification of Li deposition behavior on anodes with a porous interlayer in Li-free all-solid-state batteries

“…1,2 Because cathode active materials are solely used as the Li source in Li-free ASSBs and no Li metal is involved in the initial battery assembly process, the energy density of the entire cell can be signicantly increased. [3][4][5] Furthermore, the absence of Li metal during cell assembly can streamline the production process. 6 For Li-free ASSBs to achieve high-capacity retention over many cycles, high reversibility is particularly required during repeated Li deposition and stripping processes within the anode because the Li supply is very limited without excess in Li-free ASSBs.…”