Unit 1 Battery Technology

Vocabulary flashcards covering key terms and definitions from the battery technology lecture notes.

Redox reaction

A chemical process involving electron transfer between species, comprising oxidation and reduction.

Anode

Electrode where oxidation occurs; in a galvanic cell it is negative and releases electrons.

Cathode

Electrode where reduction occurs; in a galvanic cell it is positive and accepts electrons.

Electrolyte

Ionic conductor that allows movement of ions between electrodes in a battery.

Electrochemical cell

A device with electrodes and electrolyte that converts chemical energy to electrical energy (or vice versa).

Galvanic cell

Spontaneous electrochemical cell that produces electrical energy from a chemical reaction.

Electrolytic cell

Non-spontaneous electrochemical cell driven by external current to force a reaction.

Salt bridge

Ionic conduit connecting half-cells to balance charge during operation.

Daniel cell

Classic galvanic cell with zinc anode and copper cathode connected by a salt bridge.

EMF (cell potential)

Electromotive force; the voltage that drives current in a cell.

Standard emf (E0cell)

EMF of a cell under standard conditions (1 M, 298 K, 1 atm).

Standard electrode potential (E0)

Potential of a half-cell with unit activities, used to build the electrochemical series.

Nernst equation

Relates electrode/cell potential to concentrations: E = E0 − (RT/nF) ln Q; at 298 K, E = E0 − (0.0592/n) log Q.

Faraday constant (F)

Charge per mole of electrons (approximately 96,485 C/mol).

Lead-acid battery

Rechargeable battery with Pb and PbO2 electrodes in sulfuric acid; ~2.1 V per cell; common in cars.

PbSO4

Lead sulfate, the solid product that forms on electrodes during discharge in lead-acid batteries.

Sulfation

Formation of large PbSO4 crystals that impedes recharge in lead-acid batteries.

Nickel-metal hydride (NiMH) battery

Rechargeable battery with NiOOH positive electrode and hydrogen-absorbing alloy negative electrode.

NiMH advantages

Higher energy density and safer/environmentally friendlier than NiCd; good cycle life.

NiMH disadvantages

Higher self-discharge, temperature sensitivity, and slower charging than some newer chemistries.

Lithium-ion battery (Li-ion)

Rechargeable battery using intercalation of Li+ between graphite anode and metal oxide cathode.

Li-ion advantages

High energy density, lightweight, no memory effect, long cycle life.

Li-ion limitations

Flammable liquid electrolytes risk of fire; safety concerns; drive toward solid-state electrolytes.

Solid-state battery

Battery with solid electrolyte offering higher safety and potential energy density.

Sodium-ion battery (Na-ion)

Battery using Na+ ions, abundant sodium; potential lower cost but generally lower energy density than Li-ion.

Flow battery (VRFB)

Rechargeable battery where energy is stored in external liquid electrolytes circulated through a cell.

Solid polymer electrolyte

Gel or solid polymer electrolyte; safer with high energy density but variable ionic conductivity.

Fuel cell

Cell that converts chemical energy from a fuel and oxidant into electricity with continuous reactant supply; not stored energy.

PEM fuel cell

Proton exchange membrane fuel cell using a solid polymer electrolyte; high power density, operates around 80°C, Pt catalyst.

Methanol fuel cell

Fuel cell using methanol as fuel with acid electrolyte; Pt catalyst; emissions include CO2.

Environmental impact of battery production

Impact from resource extraction, energy use, chemicals, water use, and end-of-life disposal.

End-of-life management

Recycling and safe disposal practices to minimize environmental harm from batteries.

Energy density

Stored energy per unit mass or volume (Wh/kg or Wh/L).

Power density

Available power per unit mass or volume (W/kg or W/L).

Capacity

Total charge stored; typically expressed in ampere-hours (Ah).

Cycle life

Number of charge–discharge cycles before performance degrades beyond usefulness.

Shelf life

Storage duration before a battery’s performance degrades significantly.

Energy efficiency

Ratio of energy delivered during discharge to energy required during charging.

Thermal runaway

Uncontrolled exothermic reaction in a battery leading to fire or explosion.