Basic Components of a Power Battery (Simplified Version)

A power battery is essentially a **”little box with electricity”**, with an internal structure consisting of three layers:

Core: Four main materials (accounting for approximately 70% of the battery cost)

Positive electrode (energy source)

Negative electrode (energy storage tank)

Electrolyte (ion blood)

Separator (safety isolation membrane)

Auxiliary materials: Conductive agent, binder, copper foil/aluminum foil, tabs

Function: To fix the four main materials, conduct electricity, and draw current.

Outer shell and PACK: Aluminum shell/steel shell, cover plate, BMS, wiring harness, thermally conductive adhesive

Function: To encapsulate, protect, and manage battery safety and temperature.

In short: Positive, negative, electrolyte, and membrane are the soul; auxiliary materials form the skeleton; the outer shell is the armor.

Four Core Materials (Simplified Explanation)

Cathode Material – The “Energy Heart” of the Battery

Function: Determines battery voltage, capacity, and range; highest cost (approximately 40%).

Mainstream Types:
Lithium Iron Phosphate (LFP): Inexpensive, safe, long lifespan → Energy storage + economical electric vehicles
Ternary Lithium (NCM/NCA): High energy density, long range → High-end electric vehicles

Anode materials – the battery's "energy storage warehouse"

Function: Stores lithium ions during charging and releases them during discharging; determines charging speed and cycle life; costs approximately 10%–15%.

Mainstream types:
*Artificial graphite: Mainstream (90%+), stable and inexpensive.
*Natural graphite:High capacity, low cost.
*Silicon-based anode: Next-generation, 3 times the capacity of graphite, strong fast charging (currently in mass production).

Electrolyte – The “Ion Blood” of a Battery

Function: Dissolves lithium salts, transports lithium ions between the positive and negative electrodes, determines low-temperature performance, fast charging, and lifespan, and accounts for approximately 10%–15% of the battery cost.

Composition: Lithium hexafluorophosphate (solute) + organic solvent + additives

Separator – The Battery's "Safety Membrane"

Function: Separates the positive and negative electrodes, preventing short circuits and fires. Only allows lithium ions to pass through. It is as thin as a human hair (5–12 μm) and costs approximately 10% of the battery’s capacity.

Mainstream Types:
Wet Process Separator: High strength, uniform pore size → Power + High-end Energy Storage
Dry Process Separator: Inexpensive, heat-resistant → Low-end Energy Storage + Consumer Electronics

Auxiliary Materials and Structural Components (Brief)

Conductive Agents: Carbon Black, Carbon Nanotubes
Binders: Positive Electrode PVDF, Negative Electrode SBR/CMC
Copper Foil (Negative Electrode Current Collector)
Aluminum Foil (Positive Electrode Current Collector)
Structural Components

In short, a power battery = positive electrode + negative electrode + electrolyte + separator + auxiliary materials + casing.

Understanding Power Batteries in Simple Terms: What are the Four Core Materials?