Safety First: How The Lithium Ion Battery is Engineered to Keep EVs Secure

EV battery safety is a crucial aspect of the transition to electric mobility, as it affects the performance, reliability, and environmental impact of EVs. Battery safety involves preventing and mitigating the risks of thermal runaway, fire, explosion, leakage, and other hazards that may occur due to electrical, mechanical, or thermal abuse of the battery.

Lithium Ion Battery technology sees widespread action in electric vehicles (EVs) due to their high energy density, long cycle life, reliability, and cost-effectiveness. The Lithium Ion Battery consists of a cathode, an anode, and a liquid electrolyte that facilitates lithium-ion movement from the anode to the cathode. However, beyond its performance benefits, the engineers behind these batteries have also prioritized safety measures to ensure the secure operation of EVs.

This edition of Battery Decoded aims to overview the recent advances in EV battery safety, the ground that has been covered for some time, and what’s next. 

Fundamental Safety Advantages of Lithium Ion Battery Technology

One of the key safety features of lithium-ion batteries is their built-in protection circuitry. This circuitry helps monitor and control various parameters such as voltage, current, and temperature. It acts as a safeguard against overcharging, over-discharging, and short circuits that could potentially lead to thermal runaway or even fires. 

The Lithium Ion Battery also features a porous separator, which is vital in maintaining EV safety, as it ensures that the anode and the cathode do not come in direct contact with each other. The separator is engineered to prevent thermal runaway, which is a condition where the Lithium Ion Battery temperature increases uncontrollably, leading to a blazing fire or explosion. 

The separator is typically made of a polymer material that melts when the temperature exceeds a certain threshold, shutting down the battery. In addition to the separator, the battery management system (BMS) is another critical component that ensures battery safety and is also responsible for on-the-go battery diagnostics and maintenance.

The BMS monitors the battery’s state of charge, temperature, and voltage, and controls the charging and discharging process to prevent overcharging, over-discharging, and overheating.

Overall, lithium-ion batteries are engineered with multiple safety features to ensure that they are safe and secure for use in EVs.

Preventive Measures For Safety in Electric Vehicle Batteries

To prevent safety hazards associated with Lithium Ion Battery applications in EVs, it is important to follow the manufacturer’s instructions and use only authorized batteries and charging equipment. H ty hazards:

1. Proper handling: A Lithium Ion Battery should be handled with care and stored in a cool, dry place away from direct sunlight and heat sources. Each EV manufacturer provides user manuals for the safe operation of the EV, and EV owners need to be familiar with them for an optimal and safe experience.

    

2. Safe Procurement and Standardized Guidelines: Official OEM equipment and affiliated sellers are recommended for procurement, in addition to the review of various local and international industry-standard safety guidelines.

    

3. Regular maintenance: Regular maintenance of the battery, including checking for signs of damage or overheating, can help prevent safety hazards.

    

4. Battery management system (BMS): The Lithium Ion Battery BMS monitors the battery’s state of charge, temperature, and voltage, and controls the charging and discharging process to prevent overcharging, over-discharging, and overheating.

    

5. Porous separator: The separator is vital in maintaining battery safety, as it keeps the anode and the cathode from coming into direct contact with each other. It is engineered to prevent thermal runaway, which is a condition where the battery temperature increases uncontrollably, leading to a fire or explosion. It typically has a porosity of 40% and is made of PE or plastics.

    

6. Fire suppression systems: Fixed fire suppression systems are increasingly being installed inside the Electric Vehicle battery technologies to improve their safety.
   
   

   Also Explore: Types of Batteries in Electric Vehicles

7. Proper disposal: Lithium-ion batteries should be disposed of properly to prevent environmental damage, which now typically entails reuse in 2nd life battery applications and then end-of-life recycling since the advancement of Extended Producer Responsibility (EPR) laws.

    

EVs are inclined to have a lower center of gravity than conventional ICE vehicles, as the typically longer and flatter EV batteries are placed in a wide configuration within the frame of the EV along the bottom of the vehicle, which makes them more stable and less likely to roll over. In case of a fire, the same safety procedures as for any vehicle fire should be followed.

Electric Vehicle Battery Safety Developments in The Global Ecosystem

What EV Sector Stakeholders Have Done For Electric Vehicle Battery Safety?

Electric vehicles (EVs) are generally considered to be as safe or safer than internal combustion engine (ICE) vehicles. EVs undergo rigorous safety testing and generally perform better than ICE vehicles in crash tests. Electric vehicle battery packs are tested for conditions such as overcharge, vibration, extreme temperatures, short circuits, humidity, fire, collision, and water immersion (a recent development). 

• Electric vehicles see the inclusion of additional safety features that shut down the EV’s electrical circuits when they detect a collision or short circuit.

   

• Electric Vehicle Battery manufacturers have focused on innovating new battery chemistries, materials, and architectures that can enhance the safety, performance, and durability of EV batteries. 

• EV manufacturers have invested in improving the design, engineering, and quality control of their battery systems, as well as developing advanced battery management systems (BMS) and fast-charging solutions.

   

Various automakers are amidst the challenge of addressing safety concerns around EVs. As car companies lower the costs of batteries and address range anxiety issues around EVs, safety considerations will be paramount.

What Governments Have Done For Electric Vehicle Battery Safety

Governments are also taking steps to ensure the safety of Electric Vehicle batteries. For example, the European Union has established a regulatory framework for the safety of electric vehicles, which includes safety requirements for battery systems, charging systems, and electric powertrain systems. The National Highway Traffic Safety Administration (NHTSA) is advancing proposals to increase safety parameters, including mitigating fire during normal vehicle operations, charging, and post-crash, for propulsion batteries in electric vehicles. 

As with any new and disruptive technology, it is vital that the industry develops and implements best practices and safety standards, and employs the right combinations of battery chemistry, cell design, BMS, and Battery Thermal Management Systems (BTMS) to minimize the risks of such incidents. Many governments have enacted or updated regulations and policies to ensure the safety of EV batteries, both in use and after their end-of-life. 

Recent Policy Developments in Electric Vehicle Battery Safety: 

• The US Department of Transportation (DOT) issued a final rule in 2022 to enhance the safe transportation of lithium batteries by air.

   

• The US National Highway Traffic Safety Administration (NHTSA) also launched a Battery Safety Initiative in 2022 to conduct research and develop standards for EV battery safety.

   

• In India, the Ministry of Road Transport and Highways (MoRTH) extended the implementation of additional provisions in the battery safety standards to March 31, 2023, in two phases from December 2022.

   

• These provisions include stricter cell-level safety checks, thermal propagation tests, temperature sensors, and audio-visual warnings for EV batteries.

   

• The European Commission adopted a proposal for a new regulation on batteries and waste batteries as of 2020, which is aimed at ensuring the sustainability and safety of batteries throughout their life cycle.

   

What Standards Organizations Have Done For Electric Vehicle Battery Safety

Standards organizations have developed or revised various standards and guidelines to harmonize the safety requirements and testing methods for EV batteries. For example: 

• The International Organization for Standardization (ISO) published the ISO 6469 series of standards in 2019, which cover the onboard electrical energy storage, functional safety, and protection of persons against electrical hazards of EVs.

   

• The International Electrotechnical Commission (IEC) published the IEC 62660 series of standards in 2018, which specify the performance and reliability testing of lithium-ion battery cells and modules for EVs.

   

• The Society of Automotive Engineers (SAE) published the SAE J2929 standard in 2013, which defines the minimum safety criteria for lithium-based rechargeable battery systems for EVs.

   

• The SAE also published the SAE J3072 standard in 2015, which guides the interoperability, safety, and performance of plug-in hybrid and battery-electric vehicles connected to the utility grid.

   

To Conclude

Overall, EV manufacturers, battery manufacturers, standard organizations, and governments are taking several steps to ensure the safety of EVs. These include rigorous safety testing, additional safety features, and the implementation of continually updated best practices and safety standards. Governments are also establishing regulatory frameworks for the safety and sustainability of electric vehicles. 

Based on official sources, the industry has planned to make batteries safer by pursuing the following goals:

• Developing new battery technologies that can prevent or mitigate the thermal runaway phenomenon, such as solid-state batteries, bipolar batteries, and aqueous batteries.
• Improving the thermal management and fire suppression systems of EV batteries, such as using phase change materials, liquid cooling, and fire retardant additives.
• Enhancing the recycling and reuse of EV batteries, such as using modular design, eco-friendly materials, and circular economy principles. India’s Battery Waste Management Rules are an example of legislative progress in EPR.
• Establishing a global framework for the safety certification and regulation of EV batteries.

   

By innovating and engineering lithium-ion batteries with robust safety features and implementing stringent quality control measures throughout production processes, manufacturers and R&D teams alike are continually ensuring that these energy storage solutions not only provide efficient power but also prioritize user safety and environmental sustainability.

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