Q.Describe, in outline, the basic working principle of a lithium-ion (Li-ion) battery during discharge, naming the typical electrode materials and the role of lithium-ion movement between the electrodes.

[!TLDR] On discharge, $\text{Li}^{+}$ ions move from the graphite negative electrode to the metal-oxide positive electrode through the electrolyte, while electrons flow through the external circuit. [!ANSWER] Negative electrode (typically graphite, $\text{LiC}_6$) releases $\text{Li}^{+}$ ions, which migrate through a non-aqueous electrolyte to intercalate into the posit …

A lithium-ion battery stores and releases energy not by dissolving and depositing bulk metal (as the Daniell cell or dry cell do), but by shuttling $\text{Li}^{+}$ ions in and out of the layered crystal structures of its two electrode materials, a process called intercalation — earning it the nickname 'rocking-chair' battery. The negative electrode is typically graphite, which can host lithium atoms between its carbon layers (as $\text{LiC}_6$); the positive electrode is typically a lithium transition-metal oxide such as $\text{LiCoO}_2$. During discharge, lithium atoms at the graphite electrode are oxidized to $\text{Li}^{+}$ ions, releasing an electron to the external circuit, and the $\text{Li}^{+}$ ion migrates through a non-aqueous, lithium-ion-conducting electrolyte (since $\text{Li}$ reacts violently with water) to the positive electrode, where it intercalates back into the metal-oxide lattice as the corresponding metal ion is reduced. The electrons released at the negative electrode travel through the external circuit to the positive electrode, doing electrical work along the way — this electron flow is the current the battery delivers. On charging, an externally applied voltage forces this whole process to run in reverse: $\text{Li}^{+}$ ions move back out of the metal oxide and re-intercalate into the graphite. Because no bulk chemical transformation of the electrode framework occurs — only l …

Describe the intercalation mechanism (ion movement between two host lattices) rather than a bulk metal-dissolution mechanism, and separate the path of the lithium ion (through t …

Describing a Li-ion battery as if lithium metal itself dissolves and deposits at the electrodes, the way zinc and copper do in a Daniell cell — the actual mechanism is ion intercalatio …