Xiaomi Cars Hit by Another Out-of-Control Fire! Sparks Discussions on What Material Can Be the "Final Safety Guarantee"

On October 13, Zhuanshu Shijie reported that an accident involving a new energy vehicle occurred on Tianfu Avenue in Chengdu in the early morning. A vehicle suspected to be a Xiaomi SU7 Ultra caught fire after a high-speed collision. Rescue personnel on the scene reported that the car doors could not be opened, ultimately requiring firefighters to use an electric saw to break them open. The accident exposed safety hazards in new energy vehicles regarding the door unlocking mechanism after a collision, the design of hidden door handles, and battery thermal runaway protection.

Image source: Dahe Daily

Concealed Door Handles: Design Controversies and Technical Limitations

The hidden door handles have become standard in new energy vehicles due to reduced wind resistance and an enhanced technological feel, but the controversy over their safety has never subsided. In this incident, several witnesses described..."The door handle cannot be pressed out, and the emergency switch cannot be found." This is highly similar to the issues exposed in the high-speed collision incidents of the 2024 Wenjie M7 in Yuncheng, Shanxi, and the 2025 Xiaomi SU7—where the high-voltage system lost power after the collision, resulting in the failure of electronic unlocking, and the hidden door handles lacking mechanical redundancy design became an obstacle for rescue.

From a technical perspective, hidden door handles are classified into rotary (lever) and push type (electrically controlled pop-out). Rotary door handles typically retain a manual press function, allowing mechanical release even if the electric system fails. Push type handles, however, rely entirely on motor-driven operation and may completely fail in the event of a power outage. A more severe issue lies in the accessibility of emergency mechanisms: in some models, interior handles are concealed in deep recesses or beneath touch panels, requiring passengers to fumble for unlocking in emergency situations.In case of collision, an ordinary car door can be opened in 10 seconds, while after an electric vehicle catches fire, the golden escape time is usually only 30 seconds to 1 minute. Moreover, door handle sensors are often located at the front of the vehicle body and are easily damaged during a collision, leading to functional failure.

Ministry of Industry and Information Technology's new regulation: Mandatory mechanical redundancy design.

Regarding this security risk, the Ministry of Industry and Information Technology...In September 2025, a draft for the mandatory national standard "Safety Technical Requirements for Automobile Door Handles" will be released for public consultation. The core requirements of the new regulation include: each car door must be equipped with an external handle that has a mechanical release function, ensuring that the door on the non-collision side can still be opened mechanically after a collision or thermal event involving the battery; the external door handle must provide a hand operation space of no less than 60mm×20mm×25mm, and safety signs for hidden internal door handles and emergency internal door handles must be standardized. A transition period is set for implementation on January 1, 2027. New model type approvals applied for after July 1, 2027, must meet the requirements, while already approved models must complete rectification by July 1, 2028.

If the new regulations are implemented, fully concealed door handles may be banned due to a lack of mechanical redundancy, and designs that comply with the new regulations may become mainstream. Currently, the market is approximately...60% of new energy vehicles are equipped with hidden door handles, but most do not have mechanical redundancy features. Automakers need to adjust their design plans, such as incorporating mechanical door handles within the hidden handles or enhancing safety through solutions like backup power supplies and collision sensors.

Passive fire safety: Limitations of plastic flame retardancy

The vehicle was severely burned in the accident, highlighting the urgency of battery thermal runaway protection. Xiaomi uses modifications in material applications.High-performance plastics such as PPE, PPS, PC, and ABS achieve flame retardancy and high-temperature resistance for battery packs, with electrical insulation components using PPS material demonstrating excellent CTI value decay control. However, the self-ignition incident of Anhui SU7 proves that solely relying on material flame retardancy has its limitations. Systematic design flaws such as the strength of the battery pack protection structure, emergency response mechanisms after collisions, and electrical system stability are the main causes.

The role of flame-retardant plastics in fires mainly lies in slowing the spread of the fire, thereby gaining time for rescue operations. For example, modified...Materials such as PPE, PPS, PC, and ABS can withstand high temperatures and reduce the release of combustible substances, but they cannot prevent the spread of thermal runaway within a battery. True safety requires the construction of a "materials-structure-system-emergency" four-dimensional framework: using high-performance materials to establish a physical protection baseline, optimizing collision energy transmission paths through reasonable structural design, ensuring the accuracy of intelligent driving decisions with reliable system algorithms, and ultimately guaranteeing personnel escape capabilities in extreme scenarios through intuitive emergency design.

Xiaomi's Safety Challenges: A Look at Systemic Risks from Recalls

Xiaomi has conducted two large-scale recalls this year, both pointing to defects in the autonomous driving system.In September 2025, more than 116,000 SU7 vehicles were recalled due to defects in the L2-level autonomous driving system's ability to recognize extreme scenarios, which affected the highway navigation assist driving function's capability to identify, warn, or respond inadequately in extreme situations. Previously, in January 2024, 30,931 vehicles from the same series had been recalled due to a failure in detecting static obstacles caused by a software timing synchronization issue in the intelligent parking assist function. Both recalls were resolved through OTA updates, but the exposed defects exhibited a progressive characteristic: expanding from static parking scenarios to high-speed dynamic scenarios, covering the core functionality chain of intelligent driving.

The spontaneous combustion incident in Anhui points to deeper issues. Investigation reveals that despite the use of high-performance flame-retardant materials in the vehicle, the fire spread rapidly after the collision, resulting in the death of three people. Industry experts indicate that when the autonomous driving system fails to make decisions under complex road conditions, or when the collision protection structure fails to effectively absorb the impact, even the most advanced flame-retardant materials cannot prevent the spread of thermal runaway. This requires car manufacturers to transcend traditional physical protection thinking and ensure the visibility and reliability of emergency escape routes in extreme scenarios.

Conclusion: Safety is the existential proposition of the smart car era.

The accident on Tianfu Avenue in Chengdu is not only a tragedy but also a profound warning about the safety design of new energy vehicles. While pursuing a sense of technology, ensuring the safety of users' lives will be an unavoidable issue for car companies. With the advancement of new regulations by the Ministry of Industry and Information Technology, the regulatory standards in the Chinese market are gradually being improved, while globally, the United States...The NHTSA has also launched an investigation into door defects in car manufacturers like Tesla. In the future, safety redundancy design will become the "standard feature" for new energy vehicle doors, and the safety of consumers' lives will ultimately surpass any design considerations. True safety is not about avoiding all accidents, but ensuring that when accidents occur, the system can minimize harm and provide reliable escape routes for occupants. This safety storm, triggered by defects in autonomous driving systems, will eventually propel the industry from "material innovation" to a qualitative change in "system safety"—and this is the most urgent survival issue in the era of smart cars.