In-situ visualization of the space-charge-layer effect on interfacial lithium-ion transport in all-solid-state batteries

Abstract

The space charge layer (SCL) is generally considered one of the origins of the sluggish interfacial lithium-ion transport in all-solid-state lithium-ion batteries (ASSLIBs). However, in-situ visualization of the SCL effect on the interfacial lithium-ion transport in sulfide-based ASSLIBs is still a great challenge. Here, we directly observe the electrode/electrolyte interface lithium-ion accumulation resulting from the SCL by investigating the net-charge-density distribution across the high-voltage LiCoO2/argyrodite Li6PS5Cl interface using the in-situ differential phase contrast scanning transmission electron microscopy (DPC-STEM) technique. Moreover, we further demonstrate a built-in electric field and chemical potential coupling strategy to reduce the SCL formation and boost lithium-ion transport across the electrode/electrolyte interface by the in-situ DPC-STEM technique and finite element method simulations. Our findings will strikingly advance the fundamental scientific understanding of the SCL mechanism in ASSLIBs and shed light on rational electrode/electrolyte interface design for high-rate performance ASSLIBs.

Bidirectionally Compatible Buffering Layer Enables Highly Stable and Conductive Interface for 4.5 V Sulfide‐Based All‐Solid‐State Lithium Batteries

“…The total conductivity of the synthesized LPSCl SEs using blocking stainless steel electrodes was 3.2 × 10 −3 S•cm −1 as reported previously. [26] First-Principles Calculations: Based on density functional theory (DFT), the first-principles calculations in this work were performed to investigate the potential decomposition reactions and Li-ion transport dynamics at the interface. The calculations were achieved by Vienna Ab initio Simulation Package (VASP) within the projector augmented-wave (PAW) approach, and the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation functional was employed.…”

“…[25] Therefore, the LZPO-LCO/In-Li all-solid-state cell shows a much lower overpotential than LCO/In-Li all-solid-state cells (Figure S7a, Supporting Information), indicating a smaller interface impedance with the LZPO buffering layer. [26] After 100 cycles, it can be found that the LCO/In-Li all-solid-state cell shows a discharge capacity of 94.1 mAh•g −1 (Figure 3b) and much larger overpotential (Figure S7b, Supporting Information). By contrast, the LZPO-LCO/In-Li all-solid-state cell can still exhibit a high discharge capacity of 136.9 mAh•g −1 , which is nearly 145% of that without the LZPO buffering layer.…”

Toward High Performance All‐Solid‐State Lithium Batteries with High‐Voltage Cathode Materials: Design Strategies for Solid Electrolytes, Cathode Interfaces, and Composite Electrodes

“…[ 118 ] Very recently, Wang et al adopted the in situ differential phase contrast scanning transmission electron microscopy technique to investigate the SCL effect at LCO–Li 6 PS 5 Cl interface. [ 119 ] Undoubtedly, these important techniques will indicate new approaches and insights for studying the SCL at AM–SE interfaces in the future.…”

Advanced low-temperature solid oxide fuel cells based on a built-in electric field

“…The BIEF is also applied in lithium-ion batteries. Qiao et al [25] demonstrated a BIEF to reduce the space charge layer formation and boost lithium-ion transport in all-solid-state lithium-ion batteries by an in-situ differential phase contrast scanning transmission electron microscopy technique and finite element method simulations.…”

“…According to our previous research, the BIEF can be formed by a Schottky heterojunction [24] , intrinsicnegative (i-n) heterojunction [12] and p-n heterojunction [25] . In a Schottky heterojunction, the BIEF can be built up simply at the interface of the metal (electrode) and semiconductor (electrolyte) regions.…”