Question

(a) The nonrechargeable lithium batteries used for photography use lithium metal as the anode. What advantages might be realized by using lithium rather than zinc, cadmium, lead, or nickel? (b) The rechargeable lithiumion battery does not use lithium metal as an electrode material. Nevertheless, it still has a substantial advantage over nickel-based batteries. Suggest an explanation.

Short answer

Lithium anodes in nonrechargeable batteries are advantageous due to their lightweight nature, high electrochemical potential, and high specific capacity. These properties result in lighter batteries with higher energy density and longer-lasting power. Rechargeable lithium-ion batteries, despite not using lithium metal as an electrode, still have advantages over nickel-based batteries due to their efficient working mechanism, higher energy density, and better charge retention.

Step-by-step solution

Advantages of Lithium Anodes in Nonrechargeable Batteries

There are a few key properties of lithium that make it advantageous over other metals like zinc, cadmium, lead, or nickel when used as an anode material in nonrechargeable batteries. These include: 1. **Lightweight:** Lithium is the lightest metal in the periodic table. This means that using lithium in batteries results in lighter batteries, which is particularly important for applications like photography that often require portable power sources. 2. **High electrochemical potential:** Lithium has a high electrochemical potential, which means that it can release a higher voltage upon discharge relative to other common anode materials. This high voltage results in higher energy density, enabling a lithium-based battery to provide more energy for the same volume of battery material. 3. **High specific capacity:** Lithium has a high specific capacity, which means that it can store a large amount of charge per unit mass. This allows for a longer-lasting battery, as it can store more energy in a smaller and lighter package.

Rechargeable Lithium-ion Batteries vs. Nickel-based Batteries

Rechargeable lithium-ion batteries do not use lithium metal as an electrode material, but they still have advantages over nickel-based batteries. There are a few reasons for this, including: 1. **Working mechanism:** Unlike other batteries that rely on metallic electrodes, lithium-ion batteries work based on the movement of lithium ions between positive and negative electrodes through an electrolyte. This allows for a more efficient transfer of charge, resulting in higher energy efficiency and longer cycle life for the battery. 2. **Higher energy density:** Lithium-ion batteries generally have a higher energy density than nickel-based batteries due to the efficient working mechanism mentioned above. This means that they can store more energy within a smaller and lighter battery, making them preferable for applications that require portable power sources or devices with limited space. 3. **Better charge retention:** Lithium-ion batteries tend to retain their charge better when not in use compared to nickel-based batteries. This means that they have a lower self-discharge rate, allowing them to hold onto their stored energy for more extended periods without significant losses. Overall, these advantages make rechargeable lithium-ion batteries a suitable choice over nickel-based batteries for many applications, despite not using lithium metal as an electrode material.