The half-reactions are:

Zn(s) + 2OH−(aq) → ZnO(s) + H2O(l) + 2e− 
  
    
      
        
        
      
    
    {\displaystyle \qquad \qquad }
   [E0oxidation = -1.28 V]
2MnO2(s) + H2O(l) + 2e− → Mn2O3(s) + 2OH−(aq)
  
    
      
        
      
    
    {\displaystyle \qquad }
   [E0reduction = +0.15 V]Overall reaction:

Zn(s) + 2MnO2(s) ⇌ ZnO(s) + Mn2O3(s)
  
    
      
        
        
      
    
    {\displaystyle \qquad \qquad }
   [E0total = +1.43 V]The ZnO is prone to clumping and will give less efficient discharge if recharged again. It is possible to recharge these batteries but is due to safety concerns advised against by the manufacturer. Other primary cells include zinc-carbon, zinc-chloride, and lithium iron disulfide batteries. Secondary cell
Contrary to the primary cell a secondary cell can be recharged. The first of which was the lead-acid battery invented in 1859 by French Gaston Planté. This type of battery is still the most widely used in among others automobiles.
μ
        =
        
          μ
          
            o
          
        
        +
        k
        ⋅
        T
        ⋅
        log
        ⁡
        (
        γ
        ⋅
        x
        )
        +
        Ω
        ⋅
        σ
      
    
    {\displaystyle \mu =\mu ^{o}+k\cdot T\cdot \log(\gamma \cdot x)+\Omega \cdot \sigma }
  
In this equation μ represents the chemical potential, with μ° being its reference value. T stands for the temperature and k the Boltzmann constant.