Highlights

• Dongfeng tests its new 350 Wh/kg solid‑state battery in temperatures down to –40 °C
• Battery retains roughly 72 % of its energy capacity in extreme cold
• Single‑charge range exceeds 1,000 km according to company data
• Pilot production line already delivering 0.2 GWh of solid‑state cells
• Over 180 patent applications filed for the technology
• Large‑scale production slated to start in September 2026
• Future battery targets range from 240 Wh/kg to 500 Wh/kg

Introduction

Dongfeng, the Chinese automotive giant, has begun field testing its latest solid‑state battery in one of the coldest regions of China. The trial, carried out in the northern city of Mohe, pushes the battery to temperatures as low as –40 °C and as high as –30 °C. The aim is to verify energy retention, safety and durability under harsh winter conditions.

What Happened

The test vehicle, equipped with a solid‑state pack rated at 350 Wh per kilogram, was driven on public roads in Mohe. Engineers monitored the battery’s performance while the ambient temperature hovered between –40 °C and –30 °C. According to Dongfeng, the pack kept about 72 % of its rated energy despite the severe cold. The same battery previously passed a high‑temperature test at 170 °C, demonstrating a wide operating window.

Key data from the trial include:

• Energy retention: ~72 % at –40 °C
• Reported range: over 1,000 km on a single full charge
• Charging rate: 1 C (full charge in one hour)
• Safety checks: no thermal runaway or voltage sag observed

Why It Matters

Solid‑state technology promises higher energy density, faster charging and improved safety compared with conventional lithium‑ion cells. Retaining three‑quarters of its capacity at –40 °C addresses a long‑standing barrier for electric vehicles in cold climates. Drivers in northern China, Scandinavia and parts of North America often see range loss of 30‑40 % in winter. Dongfeng’s results suggest that future EVs could maintain usable range even in sub‑zero weather.

The 1,000 km range claim also challenges the perception that solid‑state batteries are limited to niche applications. If the figure holds up in real‑world use, Dongfeng could position its EVs as long‑range competitors to premium models that rely on larger lithium‑ion packs.

Industry Impact

Dongfeng’s move adds pressure on other manufacturers that are still in the laboratory phase of solid‑state development. The company already operates a pilot production line capable of delivering 0.2 GWh of cells, and it has filed more than 180 patent applications related to the technology. Those patents cover electrode materials, electrolyte formulations and manufacturing processes.

The firm announced plans to scale up to full‑scale production in September 2026. The future product roadmap includes batteries with energy densities ranging from 240 Wh/kg to 500 Wh/kg. Such a spread would allow Dongfeng to offer both affordable city EVs and high‑performance models using the same core technology.

Competitors such as Toyota, Volkswagen and QuantumScape are also racing to commercialise solid‑state packs, but few have demonstrated cold‑weather performance at the level Dongfeng claims. The test could accelerate investment in thermal‑management systems and influence regulatory standards for battery testing in extreme climates.

What’s Next

Dongfeng will continue the Mohe trial through the winter months, extending the test to –50 °C to map the lower limits of the pack. Data from the program will feed into the design of the first production‑ready solid‑state vehicle, expected to debut at the 2026 World Power Battery Conference in Sichuan.

In parallel, the company will begin limited pilot deliveries of the battery to selected fleet partners in northern China. Those early adopters will provide real‑world mileage, charging behaviour and durability feedback before the mass‑production line ramps up.

The solid‑state battery market is poised for rapid growth, and Dongfeng’s cold‑weather validation could become a benchmark for the industry. As the technology matures, consumers can anticipate EVs that deliver long range, fast charging and reliable performance regardless of the season.