The impact mechanism of low temperature on alkaline batteries

At low temperatures, the electrochemical reaction rate decreases significantly, resulting in a reduction in battery output current. According to the Arrhenius equation, the chemical reaction rate has an exponential relationship with temperature, and a decrease in temperature will significantly slow down the electron and ion exchange efficiency between the reacting substances. For alkaline batteries, specific reaction kinetics are required for the oxidation of the zinc anode and the reduction of the manganese dioxide cathode. Low temperatures result in insufficient energy for particles in electrode materials and electrolytes, hindering efficient electrochemical reactions. This prevents zinc from being oxidized quickly, and the reduction reaction of manganese dioxide is also inhibited, resulting in the battery being unable to provide stable current.
Electrolyte viscosity increases
The electrolyte in alkaline batteries is usually potassium hydroxide solution, which is responsible for providing OH⁻ ions to participate in the electrochemical reaction. At low temperatures, the viscosity of the electrolyte increases significantly, causing ions to migrate slower. Ion migration is an important part of electron exchange within the battery. When the movement of hydroxide ions in the electrolyte becomes sluggish, the battery's conductivity will be significantly reduced.
At low temperatures, the increased viscosity of the electrolyte will increase the internal resistance of the battery, preventing current from flowing smoothly, causing the battery's output voltage to drop. Higher resistance not only affects the battery's instantaneous discharge capability, but also causes the battery to heat up, further reducing the battery's energy efficiency.
Internal battery resistance increases
In addition to an increase in electrolyte viscosity, low temperatures can also cause an increase in the resistance of other components of an alkaline battery. Typically, a battery's internal resistance increases as temperature decreases, primarily due to a decrease in the material's conductivity. Under low temperature conditions, the conductive properties of electrode materials such as zinc and manganese dioxide will weaken, affecting the conduction efficiency of electrons.