How Phase-Change Materials Help Lithium Battery Starters Work Reliably in Extreme Temperatures

Lithium battery starters find broad applications in automobiles and portable devices as they possess excellent energy density and long cycle life. Nevertheless, under harsh temperatures, particularly extremely high or low temperatures, their output can be drastically affected. Utilising phase-change materials (PCMs) to control battery temperature effectively is one solution that looks promising against this issue. This paper discusses how PCMs improve lithium battery starter performance by temperature stabilisation and avoiding thermal stress-related damage.

What Are Phase-Change Materials and How Do They Work?

Phase-change materials are substances that absorb or release large amounts of heat during their transition between solid and liquid states. When a PCM reaches its melting point, it absorbs heat without a significant rise in temperature, effectively acting as a thermal buffer. 

PCMs are incorporated in lithium battery starters in the vicinity of or inside the battery pack to manage temperature extremes. PCMs preclude overheating by trapping excess heat produced by the battery's use or charging. 

How Do PCMs Enhance Lithium Battery Starter Performance in Severe Temperatures?

Severe temperatures present two significant issues for lithium battery starters:

• High Temperatures: High temperatures hasten chemical reactions within the battery, leading to loss of capacity, accelerated deterioration, and safety hazards like thermal runaway.

• Low Temperatures: Low temperatures slow down the chemical activity of the battery, decreasing its capacity to provide power and even leading to irreversible damage.

PCMs address both concerns by keeping the battery temperature within a more stable, safer range. When the battery gets hot during operation, the PCM melts and takes in heat, keeping the battery from getting too hot to damage. 

This heat keeps the battery chemically active, and starting power is guaranteed even at sub-freezing temperatures. 

What Are the Key Properties of PCMs for Battery Thermal Management?

• Melting Temperature: The PCM’s melting point should align with the battery’s ideal operating temperature, typically below 40°C, to absorb heat effectively without overheating.

• Latent Heat Capacity: A high latent heat of fusion means the PCM can absorb or release more heat during phase changes, enhancing thermal regulation.

• Thermal Conductivity: Higher conductivity enables faster heat transfer between the battery and PCM, improving temperature control.

• Cycle Stability: The PCM needs to endure repeated melting and solidification without degrading or diminishing effectiveness with time.

• Chemical Compatibility: It must be inert and safe to use with battery materials to prevent corrosion or damage.

• Density and Volume: Proper volume and density of the PCM provide ample heat storage capacity within the confined space of a battery pack.

How Are PCMs Incorporated into Lithium Battery Starter Designs?

PCMs are usually integrated as a layer or encapsulating material around battery cells or modules. In some designs, composite PCMs are blended with expanded graphite or epoxy materials to improve thermal conductivity and avoid leakage upon melting. These composites are structurally stable and enhance heat spreading.

What are the benefits of using PCMs on lithium battery starters?

• Increased Safety: PCMs minimise the chance of thermal runaway and fire by minimising temperature spikes.

• Improved Performance: Consistent temperatures preserve battery capacity and power output, allowing for consistent starts.

• Increased Battery Life: Thermal control slows degrading processes, prolonging overall battery life.

• Energy Efficiency: Batteries can work closer to ideal temperatures, minimising energy losses.

• Passive Operation: PCMs need no external power or moving parts, providing a low-maintenance solution.

Conclusion

Phase-change materials are revolutionising the performance of lithium battery starters at extreme temperatures. PCMs absorb and release heat during phase changes, ensuring stable battery temperatures, avoiding damage from overheating or cold. This temperature control enhances safety, reliability, and life, improving lithium battery starters in extreme conditions. For users wanting reliable starting power in all weather, PCMs provide an intelligent, energy-saving solution to temperature problems