Mobile Phone Transport Blocked? Five Key Reasons About Lithium Batteries You Must Know

From second-hand mobile phones rejected at courier lockers, to personal devices stopped during airport check-in, and bulk goods stranded in cross-border logistics, blocked mobile phone transport is a common occurrence. The core crux behind this always points to the built-in lithium battery of mobile phones—this seemingly small energy carrier has become a “high-risk product” in the logistics industry due to the inherent contradiction between its own characteristics and transportation scenarios. Data shows that in 2024, there were 423 safety accidents caused by lithium batteries in various logistics and transportation sectors in China, with mobile phone lithium batteries accounting for over 35%, directly leading to economic losses of over 180 million yuan due to transportation delays, goods damage, and other issues. Why has the lithium battery become a “stumbling block” for mobile phone transport? This article will analyze five key reasons from the perspectives of scientific principles, practical risks, and regulatory requirements, revealing the truth behind blocked mobile phone transport.

I. Key Reason 1: The “Chemical Original Sin” of Lithium Batteries—The Irreversible Risk of Thermal Runaway

The transportation risk of lithium batteries stems from the inherent characteristics of their chemical structure. Lithium-ion batteries achieve energy storage through the intercalation and deintercalation of lithium ions between the positive and negative electrodes, and this process is extremely sensitive to environmental changes. Any minor abnormality may trigger “thermal runaway,” which is also the core safety hazard of lithium batteries.

(I) The “Death Cycle” of Thermal Runaway

The electrolyte of mobile phone lithium batteries is an organic flammable liquid, with a normal operating temperature range of -20℃ to 60℃. Once exceeding this range or suffering physical damage, it may trigger a chain reaction. When the battery casing deforms due to extrusion or collision, the positive and negative electrode materials will directly contact to form a short circuit, generating a large amount of heat instantly, causing the electrolyte temperature to exceed the critical value of 80℃. At this time, the electrolyte will decompose to produce flammable gases such as methane and ethylene, and the internal pressure of the battery will rise sharply. When the pressure exceeds the bearing limit of the casing, the battery will bulge, rupture, or even explode. More dangerously, the thermal runaway process will release high-temperature flames above 600℃, accompanied by highly toxic gases containing fluorine and phosphorus. Moreover, the fire cannot be extinguished by ordinary fire extinguishers and can only be cooled down with a large amount of water, which is almost impossible to achieve in transportation scenarios.

(II) The “Risk Catalyst” in Transportation Scenarios

Links such as sorting, loading and unloading, and stacking in ordinary logistics and transportation are precisely the “breeding grounds” for thermal runaway. During express sorting, mobile phones may be squeezed or dropped by conveyor belts, with an impact force of up to 100N (equivalent to the impact of a 10kg heavy object), far exceeding the compression limit of lithium battery casings (usually 50N); in trucks or cargo holds, the pressure generated by stacking goods can reach 50kg/m², which will directly cause battery deformation; the temperature inside transport vehicles can reach up to 55℃ in summer and as low as -25℃ in winter. Extreme temperatures will damage the chemical stability of the battery, greatly reducing the threshold for triggering thermal runaway. Data shows that the probability of thermal runaway of lithium batteries in transportation scenarios is 12 times that in daily use scenarios, and mobile phones, as high-frequency transported electronic products, naturally become high-risk carriers.

(III) Real Case: “Explosion Horror” on the Sorting Line

In May 2024, a sudden fire broke out at an automated sorting center of a courier company. The cause was that a mobile phone to be sent was squeezed by the conveyor belt during sorting, and the battery casing ruptured, triggering thermal runaway. The fire spread to surrounding packages within 3 minutes, burning more than 200 items, and the sorting center was suspended for 12 hours, with direct economic losses reaching 3 million yuan. Post-incident testing by the fire department found that the mobile phone battery had a short circuit between the positive and negative electrodes due to extrusion. After thermal runaway occurred, the concentration of toxic gases produced by the combustion of the electrolyte exceeded the standard by 10 times, and on-site staff had to wear gas masks to carry out cleaning work. Similar cases occur more than 100 times a year nationwide, forcing logistics companies to “strictly guard against” mobile phone transport.

II. Key Reason 2: The “Natural Hostility” of Transportation Environments—Risk Superposition in Multiple Scenarios

Mobile phone transport involves different scenarios such as land transport, air transport, and cross-border transport, each with unique risk points. These environmental factors interact with the characteristics of lithium batteries, further increasing transportation difficulties and becoming an important reason for blocked transport.

(I) Land Transport: The Dual Test of Vibration and Temperature-Humidity

In road or railway transport, the continuous vibration generated by vehicle driving and the inertial impact during sudden braking will cause mobile phones to collide continuously in the package, and the battery part will be under repeated stress; some trucks do not have temperature control equipment. The high temperature and humidity inside the carriage in summer will accelerate battery aging, while low temperature in winter may cause electrolyte solidification, affecting battery performance. In 2023, a logistics truck traveling from Shenzhen to Beijing experienced tilting of stacked mobile phones in the carriage due to road vibration during high-speed driving. The batteries of multiple mobile phones were deformed under pressure, and one of them triggered thermal runaway. Although no fire occurred, the entire batch of more than 200 mobile phones was seized for inspection, resulting in a transportation delay of 7 days.

(II) Air Transport: The Fatal Combination of Low Air Pressure and Emergency Dilemma

Air transport has the strictest restrictions on lithium batteries, mainly due to the particularity of the high-altitude environment. The air pressure in the aircraft cargo hold is only 1/3-1/2 of that on the ground. Low air pressure will expand the volume of flammable gases generated inside the lithium battery, accelerating the explosion risk; at the same time, the cargo hold is a closed space. Once thermal runaway occurs, the fire and toxic gases cannot diffuse, and the fire extinguishing system equipped on the aircraft is ineffective against lithium battery fires (ordinary fire extinguishers cannot block the chemical reaction of lithium), which may put the entire aircraft in danger. Data from the International Air Transport Association (IATA) shows that there were 23 lithium battery safety incidents in air transport worldwide between 2023 and 2024, 12 of which were directly related to mobile phone lithium batteries, resulting in 4 emergency landings of aircraft and the burning of 1 cargo plane.

(III) Cross-Border Transport: Risk Transmission in Complex Links

Cross-border logistics involves multiple links such as multi-segment transport, multiple sortings, and customs inspections, and the risks faced by mobile phone lithium batteries are transmitted layer by layer. For example, mobile phones sent from China to Europe may experience a three-stage logistics process of “domestic land transport → air transport → European land transport,” and each stage may encounter extrusion and temperature difference changes; during customs inspection, the goods may be damaged due to improper operation during unpacking and handling. In addition, cross-border transport takes a long time. If the packaging of lithium batteries is poorly ventilated during long-term storage, heat may accumulate due to their own slight heat generation, triggering thermal runaway. In 2024, a batch of second-hand mobile phones sent from Guangzhou to Germany had 3 mobile phone batteries bulge due to high temperature in the container during cross-border transport, and the entire batch of goods was detained by German customs, causing the shipper to lose more than 500,000 yuan.

III. Key Reason 3: The “Rigid Constraints” of Regulatory Policies—The Safety Red Line Throughout the Chain

To prevent the transportation risks of lithium batteries, countries around the world have formulated strict regulatory policies, setting “safety red lines” from multiple dimensions such as packaging, declaration, and transportation qualifications. Any violation will lead to blocked transport, which is also an important reason why mobile phone transport cannot be “arbitrary.”

(I) Domestic Supervision: A Multi-Level Control System

China has established a three-level regulatory network of “laws + departmental regulations + industry standards” to implement full-process control over the transportation of mobile phone lithium batteries. The “Work Safety Law of the People’s Republic of China” classifies electronic products containing lithium batteries as “dangerous goods in limited quantities,” requiring safety testing and compliant packaging before transportation; the “Measures for the Safety Administration of Road Transport of Dangerous Goods” by the Ministry of Transport stipulates that logistics companies must inspect product qualification certificates and confirm that packaging meets standards when accepting mobile phones, otherwise they shall not accept or ship them; the State Post Bureau clearly requires that individuals must truthfully declare “containing lithium batteries” when sending mobile phones, use independent packaging, and the mobile phones must be turned off.

The penalty for violations has also been continuously increased: courier companies that illegally accept and ship mobile phones without compliant packaging may be fined up to 500,000 yuan; individuals who misdeclare or falsely report shipped items leading to safety accidents shall bear civil liability for compensation, and criminal liability shall be pursued if the circumstances are serious. In 2024, a total of 127 illegal lithium battery shipping cases were investigated and handled nationwide, 89 of which involved mobile phone transport, and the involved enterprises and individuals were subject to corresponding penalties.

(II) International Supervision: Unified Standards and Regional Rules

Globally, regulatory standards for lithium battery transport are gradually becoming unified. The United Nations “Recommendations on the Transport of Dangerous Goods – Manual of Tests and Criteria” (TDG) classifies mobile phone lithium batteries as “UN3480” dangerous goods, requiring the use of UN-certified fireproof and leak-proof packaging; the International Air Transport Association (IATA) stipulates that when individuals carry mobile phones on board, each person is limited to 1-2 units, which must be carried with the person and are prohibited from being placed in checked luggage; when sending by air courier, each shipment is limited to 1 unit and must be declared separately.

At the same time, countries have formulated regional rules: the EU’s “Battery Regulation” requires that starting from 2024, all mobile phone lithium batteries entering the EU market must be equipped with a “Digital Product Passport,” recording the full-process information of production, testing, and transportation, and non-compliant products are prohibited from transportation; the U.S. Federal Aviation Administration (FAA) stipulates that mobile phone lithium batteries must pass the “1.2-meter drop test” and “temperature cycle test” before transportation; Japan Post requires that mobile phone transport must be professionally packaged by logistics companies using designated fireproof buffer materials. These rigid constraints of policies require mobile phone transport to strictly follow procedures, and any omission in any link may lead to blocked transport.

IV. Key Reason 4: The “Uneven Quality” of Batteries—Invisible Bombs of Inferior and Modified Batteries

The quality difference of mobile phone lithium batteries further increases transportation risks, making logistics companies more cautious about mobile phone transport. The quality of mobile phone batteries on the market varies greatly. The existence of “problematic batteries” such as inferior batteries, modified batteries, and aging batteries has become an important inducement for blocked transport.

(I) Inferior Batteries: Safety Loopholes Under Cost Compression

To reduce costs, some mobile phone batteries produced by small workshops use recycled cells, inferior electrolytes, and thin iron casings. These batteries have extremely poor thermal stability, with a safe temperature threshold of only 60℃, and lack a complete Battery Management System (BMS) to real-time monitor temperature and voltage. Data shows that the probability of thermal runaway of inferior batteries is 8 times that of original batteries. Even without severe collision during transportation, they may cause accidents due to their own quality problems. Among the illegal lithium battery shipping cases investigated and handled in China in 2024, 35% involved inferior mobile phone batteries, which are likely to become “invisible bombs” during transportation.

(II) Modified Batteries: Fatal Risks of Man-Made Modifications

To improve mobile phone battery life, some users modify batteries through irregular channels, replacing them with high-capacity cells or removing battery protection devices. These modified batteries fail to meet the standards for key indicators such as charging cycle times and voltage stability, and are prone to overcharging, short circuits, and other problems. More seriously, the shell strength of modified batteries is damaged, and their compression resistance is greatly reduced. In the environment of extrusion and vibration during transportation, thermal runaway is almost inevitable. In 2023, a fire broke out at an express sorting center in Shanghai. The cause was that a modified mobile phone battery short-circuited and caught fire during transportation, burning more than 500 packages with a direct loss of 800,000 yuan.

(III) Aging Batteries: Safety Hazards After Usage Wear

Mobile phone batteries used for more than 3 years will have problems such as cell aging, capacity attenuation, and increased internal resistance, and their safety performance will drop significantly. The casing of aging batteries may develop cracks, and the electrolyte may leak. During transportation, slight vibration or temperature changes may trigger thermal runaway. Research by the International Air Transport Association (IATA) shows that the transportation accident rate of mobile phone batteries used for more than 3 years is 7 times that of new batteries. This is also an important reason why logistics companies are extra strict with the transport of second-hand mobile phones—many batteries of second-hand mobile phones are in an aging state, and the risks are difficult to predict.

V. Key Reason 5: “Human Loopholes” in Operational Links—Risk Amplification of Improper Behaviors

In addition to the characteristics of lithium batteries themselves, transportation environments, and regulatory policies, improper human operations are also an important reason for blocked mobile phone transport. From user packaging, logistics sorting to enterprise compliance operations, any negligence in any link may turn potential risks into actual problems.

(I) User Side: Incorrect Packaging and Misdeclaration/False Declaration

Common incorrect operations by ordinary users when sending mobile phones include: mixing mobile phones with hard objects such as keys and chargers, leading to hard objects hitting the battery during transportation; using thin plastic bags or cartons for packaging, lacking buffer materials, unable to resist extrusion; concealing the name of the item to avoid inspection, declaring “mobile phone” as “daily necessities.” These behaviors will directly increase the probability of battery damage and violate regulatory requirements, leading to the goods being rejected or detained. In 2024, a statistics from a courier company showed that among the rejected mobile phone transport orders, 62% had non-compliant packaging problems, and 28% had misdeclaration.

(II) Logistics Side: Rough Sorting and Illegal Mixed Loading

Improper operations by logistics companies can also amplify risks. To improve efficiency, some express sorting centers adopt a “rough sorting” model, where mobile phones are arbitrarily thrown and squeezed, and the impact force they bear far exceeds the safety limit; to save costs, some small logistics companies mix mobile phones with flammable items (such as cosmetics, alcohol products) or sharp objects (such as tools, metal parts) for transportation. Once the battery catches fire, flammable items will accelerate the spread of the fire, and sharp objects may directly pierce the battery casing. In 2024, a small logistics company in Shenzhen was fined 300,000 yuan for illegally mixing mobile phones with alcohol wipes for transportation, causing a fire, and the relevant person in charge was held accountable.

(III) Enterprise Side: Lack of Qualifications and Process Omissions

Enterprises transporting mobile phones in bulk may also face blocked transport if they lack dangerous goods transportation qualifications or fail to complete the filing procedures as required. According to Chinese regulations, enterprises transporting electronic products containing lithium batteries in bulk must obtain the “Dangerous Goods Road Transport Permit” and use special transport vehicles that meet the standards; for cross-border transport, they also need to go through documents such as import and export inspection and quarantine certificates and battery safety test reports. To save time and costs, some enterprises omit relevant processes, leading to the goods being seized during transportation. In 2024, an e-commerce enterprise was detained by customs for failing to obtain a battery safety test report when transporting 1,000 mobile phones cross-border, resulting in a transportation delay of 15 days and a direct loss of over 2 million yuan.

VI. Compliance Transport Guide: How to Avoid Blocked Mobile Phone Transport?

After understanding the five key reasons why lithium batteries cause blocked mobile phone transport, both individuals and enterprises can avoid risks through compliant operations and ensure smooth transport. The following is a practical compliance guide tested in practice:

(I) Personal Shipping: Complete the “Three Key Steps”

1. Compliant Packaging: Use a rigid packaging box (thickness not less than 3mm), fill sufficient buffer materials (such as bubble film, EPE foam) around the mobile phone to ensure no shaking; the battery part can be additionally wrapped with a layer of flame-retardant cloth to avoid hard object impact; package the mobile phone separately from the charger and data cable.
2. Truthful Declaration: Clearly mark words such as “contains lithium battery,” “fragile,” and “handle with care” on the express waybill, and do not conceal the nature of the item; when sending second-hand mobile phones, you can prepare purchase certificates or battery test reports in advance for inspection.
3. Choose Regular Channels: Select courier companies with dangerous goods transportation qualifications such as SF Express and JD Logistics, and avoid small logistics companies or “scalpers” as agents; cooperate with couriers for unpacking inspection, and re-package as required if the packaging is non-compliant.

(II) Bulk Transport by Enterprises: Adhere to the “Four Major Compliance Bottom Lines”

1. Complete Qualifications: Obtain relevant qualifications such as the “Dangerous Goods Road Transport Permit”; for cross-border transport, go through documents such as import and export inspection and quarantine certificates, battery safety test reports, and Digital Product Passports (for the EU market).

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