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Those substances of the cell which take active part in chemical combination and hence produce electricity during charging or discharging are known as ____________ materials.
passive
active
redundant
inert
active
Active materials in a chemical cell are the substances that undergo electrochemical reactions (oxidation and reduction) to facilitate the conversion of chemical energy into electrical energy. During discharge, these materials react at the electrodes to release or consume electrons, while during charging, the process is reversed.
Active materials in a chemical cell are the substances that undergo electrochemical reactions (oxidation and reduction) to facilitate the conversion of chemical energy into electrical energy. During discharge, these materials react at the electrodes to release or consume electrons, while during charging, the process is reversed.
E=E0тИТnFRTтАЛln(Q) тАФ Nernst equation representing the voltage based on active material activity (Q).
The functioning of an electrochemical cell relies on redox reactions where the active material at the anode loses electrons (oxidation) and the active material at the cathode gains electrons (reduction). These electron movements occur through an external circuit, creating current. Examples include Lead (Pb) and Lead Dioxide (PbO2тАЛ) in lead-acid batteries, or Zinc (Zn) and Manganese Dioxide (MnO2тАЛ) in primary cells.
Active materials must have high chemical affinity to participate in charge exchange.
The capacity of a cell is directly proportional to the mass of active materials present.
Active materials are typically pasted onto grid structures or contained in porous forms.
Inert materials like the cell container or grid supports do not participate in the reaction.
High energy density per unit mass
Enable reversible energy storage
Subject to mechanical degradation over cycles
Chemical shelf-life limitations
Automotive lead-acid batteries
Lithium-ion consumer electronics
Industrial UPS systems
Passive materials refer to the structural components of the cell like the separator, case, and current collectors that support the active reaction without being consumed.
Inert materials are substances added to improve conductivity or structural integrity but which do not take part in the electrochemical equation.
B is correct тАФ Active materials are defined as those substances which directly participate in the chemical redox processes required for electrical energy conversion.
Always distinguish between 'active' (participating) and 'passive' (structural/support) components in battery technology, as this is a fundamental question in power electronics and electrical machines.