Battery

Electric Battery

\usepackage{color,graphicx,circuitikz}
\begin{document}
\begin{circuitikz}[american]
 
% battery symbol `battery1`
%\draw (2,0) to [battery1, l={$\mathsf{}$}] (3,0);
 
% `battery1`, polarity marks below, without text
\draw (0,0) to [battery1, l={$\mathsf{}$}, v_=$\;$] (1,0);
 
\end{circuitikz}
\end{document}

• A Galvanic cell (or voltaic cell) is an electrochemical cell that converts chemical energy into electrical energy, consisting of:
  • two electrodes: conductors through which electric current enters or leaves the cell
    • anode ($-$): the electrode where oxidation occurs (loses electrons)
    • cathode ($+$): the electrode where reduction occurs (gains electrons)
    • the part of each electrode outside the solution is called the terminal which is used to connect the cell to a circuit
  • An electrolyte is a substance that conducts electricity by allowing ions to move and can exist either as a liquid (wet cell) or a paste (dry cell)
• A battery is a collection of electric cells connected together
• The total voltage of a series (connected end-to-end positive to negative) connection is the sum of the voltages of the individual cells $V_{\text{total}}=V_1+V_2+\dots +V_n$
• The total voltage of an opposite series connection

Example: Bunsen cell (zinc-carbon & dilute sulfuric acid)

• Electrodes:
  • Zinc anode: Zinc metal dissolves into the electrolyte as zinc ions ($\text{ce}Z{n}^{2+}$), leaving behind electrons on the zinc electrode, which becomes negatively charged.
  • Carbon cathode: The sulfuric acid electrolyte pulls electrons from the carbon electrode, making it positively charged.
• Electrolyte: The dilute sulfuric acid ($\text{ce}H2SO4$) serves as the electrolyte, allowing ions (e.g., $\text{ce}Z{n}^{2+}$) to move between the electrodes while completing the internal charge balance.
• Chemical Reaction:
  • At the zinc anode: Zinc undergoes oxidation ($\text{ce}Zn->Z{n}^{2+}+2e^{-}$), releasing electrons into the electrode and producing zinc ions.
  • At the carbon cathode: Electrons flow from the zinc anode to the carbon cathode through an external circuit, where reduction reactions can take place.
• Voltage: The zinc electrode becomes negatively charged, and the carbon electrode becomes positively charged, creating a potential difference (voltage) between the two terminals.
• Current:
  • (closed circuit) Electrons flow through the external circuit from the zinc anode to the carbon cathode, creating an electric current.
  • (open circuit) When the terminals are not connected, only a small amount of the zinc is dissolved,

• todo
  • terms
    • dry cell
    • half-cell
    • salt bridge
    • standard electrode potential
    • volatge regulator
    • State of charge (SoC)
    • State of health (SoH)
    • battery management system (BMS)
  • why does electric cars typically have only one gear?