Chery Files New Sulfide-Based Solid-State Battery Patent, Targeting 600 Wh/kg Energy Density

Chery's in-house powertrain R&D division recently disclosed a key patent for solid-state battery technology, tackling the critical challenge of interfacial stability in sulfide-based electrolytes. The patent (publication number CN122348252A) has been registered with China's National Intellectual Property Administration and aims to resolve widespread interfacial structural degradation during high-rate charge/discharge cycles — a common hurdle for next-generation solid-state batteries. According to media reports, this technology is expected to underpin Chery's upcoming premium all-electric passenger vehicle platform.

The patented approach applies a functional coating directly chemically bonded to the surface of the sulfide electrolyte substrate — replacing conventional physical isolation methods with molecular-level chemical linkages. This effectively mitigates interfacial stress and structural collapse triggered by rapid lithium-ion migration, thereby enhancing cycle durability under fast-charging conditions. This surface modification strategy will serve as a foundational architecture for Chery's future high-power, long-life solid-state battery systems.

Currently, the core bottleneck for sulfide-based solid-state batteries remains excessively high interfacial impedance between electrodes and electrolyte. Chery's solution leverages active functional groups within the coating to actively regulate electrochemical reaction kinetics, ensuring uniform ion transport across the boundary region. This chemical stabilization strategy aligns technologically with recent patents disclosed by domestic industry leaders such as BYD and CATL — for instance, BYD previously filed a patent on thermal stability of sulfide batteries, while CATL proposed dedicated interfacial boundary designs to suppress ionic current disorder. Chery's newly introduced chemical coating pathway represents an independently developed mechanical-structural variant, targeting equivalent long-term battery reliability.

This patent release coincides with a pivotal national push to pilot industrialization of solid-state batteries. At a prior battery technology launch event, Chery unveiled its self-developed "Rhino S" solid-state battery, explicitly setting 600 Wh/kg as its ultimate energy density target. Per its roadmap, this high-density sulfide battery is slated for phased integration into multiple production passenger models, with small-batch vehicle deployment targeted for 2027.

Leveraging its Wuhu headquarters — backed by over RMB 5.8 billion (approx. USD 855 million) in registered capital and a portfolio of 27,153 registered patents — Chery has built a vertically integrated, full-industry-chain proprietary technology ecosystem, including controlling stakes in 68 automotive and supply-chain enterprises. This vertical integration enables sustained, independent investment in fundamental electrochemistry R&D, reducing reliance on upstream battery suppliers.

Nonetheless, large-scale commercialization of all-solid-state batteries still faces practical constraints. CATL recently acknowledged that, due to manufacturing costs and process maturity, true mass-market adoption "remains years away." Industry consensus places domestic solid-state battery development at Technology Readiness Level (TRL) 4 — system validation in relevant environments — on the standard nine-level scale. Chery's interfacial chemical optimization is widely viewed as a critical step toward accelerating beyond pilot-scale validation and supporting its 2027 fleet deployment goal.