MSE Supplies offers High-Precision Testing System for Solid Electrolyte. It is a multifunctional test system dedicated to measure solid electrolyte samples. It adopts integrated design, including pressurization module, electrochemical test module, compaction density measurement module, and clamp, etc., which is applicable to the test of various oxides, sulfides, polymers and other kinds of electrolytes. It allows users to perform various material analysis and to acquire necessary information for R&D material evaluation and process optimization.

Importance of Electrochemical Performance of Solid Electrolyte

Driven by the rapid development of the lithium-ion battery (LIB) industry, improving the energy density and safety of the battery is an important research direction of for the LIB researchers. All-solid state battery is considered to be the most promising secondary battery with high safety and high specific energy in the future. Solid electrolyte (SE) is the most important core component, and the most important performance indicators used to judge the performance of solid electrolyte are ionic conductivity, Li-metal interface stability and full cell performance. On the one hand, the density, roughness and integrity of the pressed solid electrolyte sheet determine the conductivity of the solid electrolyte and the cycle performance of the full cell; On the other hand, the accuracy of the test results can only be guaranteed by the stable and uniform stress application and the accurate thickness measurement during the experiments. Therefore, the production and testing system that can exert stable and standardized pressure plays a key role in the development of solid electrolyte and lithium metal battery.

Testing Method of Solid Electrolyte Ionic Conductivity

1. Sample Preparation:

Oxide materials must be subject to high-temperature crystallization treatment (generally above 900 °C) to ensure good ion transport performance. Generally, the density of electrolyte sheet is>95%, and the thickness is>500 μm; In terms of electrode preparation, the electrode must be polished with sandpaper with more than 3000 meshes and sprayed with conductive gold of a certain thickness (>5 μm) , after which the good interface contact can be ensured. Grind the edge of the metal with sandpaper to prevent short circuit. Use a multimeter to ensure the electronic continuity between any two points on the surface.
The sulfide materials can directly be tested by cold compression process. During the test, a certain pressure (usually >200 MPa) must be guaranteed to ensure good ion transport performance.

2. Fixture Design:

A flat and compact contact surface, and a stable and uniform force application structure (quantifiable pressure) are required.

3. Test Device:

An electrochemical workstation system capable of measuring high frequency impedance (>1MHz) is required. A short lead with good signal shielding is also required.

4. Test Conditions:

Select appropriate temperature and humidity, quantization pressure, frequency range and amplitude voltage.

Testing Method of Electrochemical Performance of Solid Lithium Battery

1. Electrolyte Preparation:

Oxide materials must be subject to high-temperature crystallization treatment (generally above 900°C) to ensure good ion transport performance. Generally, the density of electrolyte sheet is >95%, and the thickness is >500μm. It must be with strictly polished by the sandpapers.
During the direct cold pressure test of sulfide materials, a certain pressure (usually >200MPa) must be guaranteed to have good ion transport performance.

2. Electrode Preparation:

The positive electrodes shall be prepared by scraping, screen printing, sputtering deposition and other methods. The negative electrodes shall be prepared by surface treatment, melting, physical/chemical deposition, pressing and other methods to ensure good interface contact.

3. Fixture Design:

It needs a flat and compact contact surface, and a stable and uniform force application structure (quantifiable pressure).

4. Test Conditions:

Appropriate temperature and humidity, certain quantitative pressure, and strict sealing device.

Technical Specifications:

Parameter	Solid Electrolyte Testing System
Pressure Measurement Range (T)	0.05 ~ 5
Pressure Accuracy	± 0.3% F.S
Thickness Range (mm)	0 ~ 8
Thickness Accuracy (μm)	± 10
Thickness Resolution (μm)	0.5
Sample Mould Diameter (mm)	13 (other sizes can be customized)
Temperature & Humidity Range	0 ~ 50°C / 20% ~ 90%RH
Temperature & Humidity Accuracy	±2°C / ±5%RH
Supply Voltage (V)	220 / 110 (Optional)
Power Consumption (W)	300
Environmental Temperature (°C)	20 ~ 30
Environmental Humidity at 40°C	< 80%RH

Examples:

1. Powder Production: The equipment can be used to tablet the powder samples under different pressure conditions, and the tablets obtained by SEMS are intact and free of cracks.

2. Ionic Conductivity: Through the electrochemical impedance spectroscopy (EIS) module of SEMS, the ionic conductivity of solid electrolyte under different pressures can be obtained automatically.

3. Electronic Conductivity & Compaction Density: Through the DC polarization (DP) module of SEMS, the electronic conductivity and compaction density of solid electrolyte under different pressures can be obtained automatically.

4. Electrochemical Stability Window: Through the cyclic voltammetry (CV) module of SEMS, it is possible to analyze the electrochemical stability window of solid electrolyte under different pressure.

5. Solid State Battery Cycle Performance: Through the charge-discharge test (CD) module of SEMS, the cycle performance of solid lithium metal battery under different pressure and different electrochemical parameters can be analyzed.