Impact on performance

• Capacity
  
  
  
  • High - temperature environment: Within a certain temperature range, the capacity of lithium - ion batteries may increase slightly with the rise in temperature. This is because the increase in temperature accelerates the diffusion rate of lithium - ions in the electrode material and electrolyte, making the electrochemical reaction more likely to occur, so more lithium - ions can be inserted and extracted from the electrode, thereby increasing the discharge capacity.
  
  
  • Low - temperature environment: At low temperatures, the viscosity of the electrolyte increases, the diffusion rate of lithium - ions slows down, and the electrochemical reaction kinetics become sluggish. As a result, the battery's available capacity decreases, and the discharge curve shifts to a lower voltage range.
  
  
  
  


• Output power
  
  
  
  • High - temperature environment: The internal resistance of the battery decreases at high temperatures, which means that the battery can output larger currents and higher powers. This is beneficial for applications that require high - power output, such as electric vehicle acceleration.
  
  
  • Low - temperature environment: The internal resistance of the battery increases at low temperatures, which limits the maximum current that the battery can output, thereby reducing the output power. In extreme cases, the battery may not be able to provide enough power to start the equipment.
  
  
  
  

Impact on lifespan

• High - temperature environment: High temperatures can accelerate the degradation of the electrode material and electrolyte in the battery. For example, the positive electrode material may undergo structural changes, and the electrolyte may decompose, which reduces the reversible capacity of the battery and shortens its cycle life. Long - term exposure to high temperatures can also cause the growth of lithium dendrites, which may penetrate the separator and cause an internal short - circuit of the battery, further reducing the lifespan.


• Low - temperature environment: Although the chemical reaction rate is slow at low temperatures, the formation of lithium - ion plating on the negative electrode surface is more likely to occur. This is because the lithium - ion diffusion rate is slow, and the lithium - ions are more likely to be deposited on the electrode surface rather than inserted into the negative electrode material. Lithium - ion plating can cause irreversible capacity loss and affect the lifespan of the battery.

Impact on safety

• High - temperature environment: High temperatures increase the risk of thermal runaway in lithium - ion batteries. When the temperature rises to a certain extent, the exothermic reaction in the battery may get out of control, leading to a rapid increase in temperature and pressure inside the battery, and even causing the battery to catch fire or explode. In addition, high temperatures can also accelerate the aging of the battery's internal components, reducing the safety margin of the battery.


• Low - temperature environment: At low temperatures, the mechanical properties of the battery materials change, and the battery shell may crack or deform due to thermal stress. This can damage the internal structure of the battery and cause an internal short - circuit, increasing the safety risk. In addition, the increase in internal resistance at low temperatures may cause the battery to overheat during charging and discharging, which also poses a safety hazard.