A Flexible Electron-blocking Interfacial Shield for Dendrite-free Solid Lithium Metal Batteries

Abstract

Solid-state batteries (SSBs) are considered to be the next-generation lithium-ion battery technology due to their enhanced energy density and safety. However, the high electronic conductivity of solid-state electrolytes (SSEs) leads to Li dendrite nucleation and proliferation. Uneven electric-field distribution resulting from poor interfacial contact can further promote dendritic deposition and lead to rapid short circuiting of SSBs. Herein, a flexible electron-blocking interfacial shield (EBS) is proposed to protect garnet electrolytes from the electronic degradation. The EBS formed by an in-situ substitution reaction can not only increase lithiophilicity but also stabilize the Li volume change, maintaining the integrity of the interface during repeated cycling. Density functional theory calculations show a high electron-tunneling energy barrier from Li metal to the EBS, indicating an excellent capacity for electron-blocking. EBS protected cells exhibit an improved critical current density of 1.2 mA cm-2 and stable cycling for over 400 h at 1 mA cm-2 (1 mAh cm-2) at room temperature. These results demonstrate an effective strategy for the suppression of Li dendrites and present fresh insight into the rational design of the SSE and Li metal interface.

Design of a lithiophilic and electron-blocking interlayer for dendrite-free lithium-metal solid-state batteries

“…For reference, the result for the bare LLZTO cell is also provided in the Supplementary Materials (fig. S5), which recorded the CCD value of 0.3 mA cm −2 , consistent with previous reports (48). Our results show that the short circuit of the Ag-coated LLZTO cell occurs at a current density of 1.5 mA cm −2 upon increasing the current up to 3.2 mA cm −2 with a step of 0.1 mA cm −2 (Fig.…”

“…For reference, we plotted the relative performance standing of our hybrid full cell in comparison with those of recently reported relevant solid-state cells that have gone through various interfacial modifications (e.g., the introduction of interlayers or removal of interfacial impurities as denoted in the figure) with respect to two key demonstrated indicators of current density and long-term cycling in Fig. 5G ( 17 , 18 , 20 – 25 , 48 , 50 – 55 ) It clearly manifests that the modification with the Ag/LiF multilayer in the current work excels the previous reports, not only in the high-rate capability (2 C cathode ) but also in the long-cycle durability (over 3000 cycles). It is our belief that it is attributed to the orthogonal multifunctions of the Ag/LiF layer, which has enabled the homogeneous interfacial property during charge/discharge and allowed the operation of the lithium cell even at high current density by preventing the electronic leakage through the cell.…”

The interfacial engineering of metal electrodes for high-specific-energy and long-lifespan batteries

“…To improve the interfacial contact and kinetics, various artificial interlayers with better wettability for metallic Li are introduced. Li et al introduced subtle carbon to react with Li 2 CO 3 on the garnet SSEs in Ar at 700 °C and significantly reduced the interfacial resistances to 28 Ω•cm 2 ( Figure 7(a)) [98] . Apart from improving interfacial contact, the interlayer can facilitate the ion-conducting at the interface and block the electron infusion.…”

Scalable, thin asymmetric composite solid electrolyte for high‐performance all‐solid‐state lithium metal batteries

“…ICEs show higher room-temperature ionic conductivity (10 −4 ~10 −2 S cm −1 ), [17] wide electrochemical windows, and excellent mechanical robustness, but poor interfacial contacts or unsatisfactory stability hinder their widespread use. [20,21] Furthermore, the thickness of higher density ICEs is difficult to be reduced, [22] which is not conducive to increasing the energy density at the cell level. As the complex of SPEs and ICEs, CSEs, which inherit the flexibility from SPEs and high mechanical modulus from ICEs, have been considered the promising SSEs for ASSLMBs with excellent comprehensive performances.…”