Lithium-ion battery cells are the most important part of a battery; strictly speaking, a battery cell is the same as a battery. So what are battery cells made of? Today, we'll discuss this question.
A lithium-ion battery cell refers to a single electrochemical cell containing positive and negative electrodes. It is generally not used directly, as a fully functional battery requires the addition of protective circuitry and a casing. While battery types vary, their basic structure is largely the same; here, we will analyze lithium polymer batteries.
The battery cell consists of three main components: positive and negative electrode materials, electrolyte, and separator.
Generally, cathode materials are composed of highly conductive substances, such as lithium-ion batteries in lithium iron phosphate batteries. Cathode materials for lithium polymer batteries are mainly heterocyclic polymers such as polypyrrole (Ppy), polythiophene (PTh), and their derivatives. For example, the cathode structure of lithium cobalt oxide can be LiCoO2 (lithium cobalt oxide) + conductive agent (acetylene black) + binder (PVDF) + current collector (aluminum foil or aluminum strip).
Negative electrode materials are generally carbon materials, mainly natural graphite, coke, and carbon fiber. Currently, more advanced negative electrode layered graphite particles have adopted nano-carbon. The positive electrode structure of the negative electrode can be graphite + conductive agent (acetylene black) + thickener (CMC) + binder (SBR) + current collector (copper foil or nickel strip).
A diaphragm is a separating layer placed between the positive and negative electrodes to prevent direct short circuits between the two electrodes. The diaphragm itself is non-conductive, but electrolyte ions can pass through it.
The electrolyte in a lithium polymer battery is the carrier for energy transfer. Organic solutions are generally used, and aqueous electrolytes cannot be used.
The above is an introduction to the composition of lithium battery cells from Juda Lithium Battery, a lithium battery cell manufacturer.
