Technical Requirements for Solid Electrolytes in GB Z 214 2026 GB/Z 214-2026 and the Related Post-Treatment Processes for Solid Electrolytes

On July 30, 2026, the national standardization guiding technical document GB/Z 214-2026 "Technical Specifications for Solid Electrolytes for Solid-State Batteries for Electric Vehicles" was officially released and implemented.

This is China's first systematic technical specification for solid-state battery core materials, proposed by the Ministry of Industry and Information Technology and centralized by the National Technical Committee of Auto Standardization (SAC/TC114). The document clearly defines core indicators and corresponding test methods for ionic conductivity, electronic conductivity, electrochemical stability window, air stability, and moisture content of solid electrolytes for electric vehicle solid-state batteries.

For solid-state battery material manufacturers, product development also requires consistent specification control and test validation.

I. Main Technical Indicators in the Document

Although this document is a guiding technical document (GB/Z) rather than a mandatory national standard (GB), it represents the state's clear direction and quality benchmark for solid electrolyte technology used in solid-state batteries. According to the Standardization Law of the People's Republic of China, guiding technical documents are for reference use by relevant parties and for technical research and experimental verification.

The document provides defined indicators and test methods for material evaluation.

Ionic Conductivity: ≥1.0×10⁻³ S/cm

Ionic conductivity is the core performance indicator of solid electrolytes, directly determining battery charge-discharge efficiency. Impurity residues (such as Cl⁻, SO₄²⁻) block ion transport channels, leading to decreased ionic conductivity.

Electronic Conductivity: ≤1.0×10⁻⁹ S/cm

Excessive electronic conductivity leads to increased self-discharge and higher internal short-circuit risks. Materials must be high-purity and uniform, free from conductive impurities or defects.

Oxidation Potential: ≥4.5 V (vs. Li); Reduction Potential: ≤1.5 V (vs. Li)

The electrochemical stability window determines the battery's high-voltage tolerance. Trace moisture and impurities cause material decomposition under high voltage, directly threatening battery safety.

Air Stability: ≥80%

Ionic conductivity retention rate after 4 hours of air exposure. Sulfide-based solid electrolytes are extremely sensitive to air (water/oxygen content must be <0.1 mL/m³), decomposing to produce H₂S upon exposure, with ionic conductivity dropping sharply.

Moisture Content: ≤0.03%

Moisture reacts with sulfide electrolytes and degrades polymer-electrolyte performance. The specified test conditions, with a dew point of -45°C to -40°C, reflect the importance of moisture control.

II. How the Indicators Relate to Material Post-Treatment

Each of the five hard requirements above points to the same process core — the preparation and post-treatment of high-purity materials.

Whether it's oxide electrolytes such as LLZO and LATP, or sulfide electrolytes, their synthesis routes all share a common critical step: precipitation → filtration → washing → drying.

Taking the co-precipitation preparation of lithium lanthanum zirconate (LLZO) solid electrolyte as an example, the process chain clearly demonstrates this sequence: solution preparation → precipitation reaction → aging → washing (until the supernatant pH is neutral) → drying → mixing → calcination → grinding → pressing → sintering. Among these, "washing to neutral" and "drying" directly affect ionic conductivity and the formation of impurity phases.

These steps correspond to the filtration, washing, and drying functions of a 3-in-1 Filter-Dryer.

III. The Role of the 3-in-1 Filter-Dryer in Solid-Electrolyte Post-Treatment

Wuxi Zhanghua's 3-in-1 Filter-Dryer performs filtration, washing, and drying in one sealed vessel, reducing transfers and environmental exposure in post-treatment steps where solid electrolytes are sensitive to moisture and impurities.

1. Fully Enclosed Inert Atmosphere Operation — Meeting Air Stability ≥80%

Sulfide-based solid electrolytes are extremely sensitive to moisture and oxygen. The 3-in-1 Filter-Dryer is equipped with a standard N₂/Ar purge system that maintains a slight positive pressure inert atmosphere inside the vessel. Powder never comes into contact with the atmosphere during the entire process, effectively solving the air stability problem while eliminating dust leakage and explosion risks.

2. Deep Washing to Reduce Residual Impurity Ions

Impurity ions such as Cl⁻ and SO₄²⁻ can interfere with ion transport. The 3-in-1 Filter-Dryer uses automatic spraying and the lifting and bidirectional rotation of an S-type agitator for multi-stage counter-current washing, allowing wash liquid to reach the filter-cake interior and reduce residual ions.

3. Vacuum Low-Temperature Drying — Guarding the ≤0.03% Moisture Content Threshold

The 3-in-1 Filter-Dryer accomplishes low-temperature drying under vacuum, effectively reducing drying temperature and avoiding material decomposition or phase transitions caused by high temperatures. Combined with inert atmosphere protection and fully enclosed operation, powder moisture content is stably controlled at ≤0.03%.

4. Full Process Traceability — Meeting the Stringent Audit Requirements of the Semiconductor/Automotive Industries

The PLC+HMI system records and archives process parameters, providing data for quality documentation, vehicle-manufacturer audits, and batch traceability.

IV. Moisture Control in Solid-Electrolyte Processing

Moisture control applies to both the electrolyte and its processing environment. Sulfide solid electrolytes are commonly handled at dew points of ≤-60°C during mixing, pressing, and post-treatment to maintain ionic conductivity and interfacial stability.

This means that the entire chain from powder synthesis to electrolyte membrane formation has rigid requirements for drying equipment and enclosed operation equipment. Some industry players have already developed vacuum double-cone drying solutions for solid-state battery electrolytes, targeting moisture content below 10 ppm.

After powder synthesis, the 3-in-1 Filter-Dryer can provide enclosed inert-atmosphere handling, deep washing, and vacuum low-temperature drying to control moisture, impurities, and material exposure.

V. How the Standard Affects Material Processing

At the 2026 (10th) China Solid-State Battery Technology Innovation and Industrialization Application Seminar, "Solid Electrolyte Materials" and "Industrialization Technology for Solid-State Batteries" were listed as key topics. Meanwhile, industry leaders including CATL, BYD, Gotion High-Tech, Qingtao Energy, and EVE Energy participated as drafting units of this standard, indicating that material purity and preparation processes are moving from "company-defined" to "industry consensus."

This indicates that solid-state battery material development is placing greater emphasis on batch consistency and specification validation.

The document provides an evaluation basis; manufacturers still need equipment and process controls to maintain batch consistency.

In solid-electrolyte post-treatment, the 3-in-1 Filter-Dryer combines enclosed operation, washing, vacuum drying, and parameter recording to help control moisture, impurities, and batch consistency.

Wuxi Zhanghua Pharm & Chem Equipment Co., Ltd.

Founded in 1976 · Nearly 50 years as a core manufacturer of reaction, crystallization, filtration, and drying equipment

3-in-1 Filter-Dryer (ANFD) — Applicable for post-treatment of precursor synthesis for oxide electrolytes (LLZO, LATP, etc.) and sulfide electrolytes, serving high-purity powder preparation fields such as solid-state batteries and lithium battery materials

Contact us for technical proposals and case references.

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