Battery Principles - Interactive Visualization

Interactive visualization of battery principles - Li-ion battery structure, charging/discharging, voltage curves, energy density, and safety features

Li-ion Battery Structure

Cathode (LiCoO₂)
Anode (Graphite)
Electrolyte
Separator

Structure Controls

View Mode

Show/Hide Layers

Overall Reaction

LiₓC₆ ⇌ Li₁₋ₓCoO₂ + xLi⁺ + xe⁻

Charge/Discharge Process

Current Process: -
Li⁺ Flow: -
Electron Flow: -
State of Charge: 0%

Charge/Discharge Controls

Electrochemical Equations

Cathode: LiCoO₂ ⇌ Li₁₋ₓCoO₂ + xLi⁺ + xe⁻
Anode: 6C + xLi⁺ + xe⁻ ⇌ LiₓC₆
Cell Voltage: V_cell = E_cathode - E_anode ≈ 3.7V

Charge/Discharge Voltage Curve

Current Voltage: 3.7V
Voltage Plateau: 3.6-3.9V
Capacity: 0mAh/g

Voltage Curve Controls

Curve Type

Nernst Equation

E = E° - (RT/nF)ln(Q)

E: Electrode potential
E°: Standard potential
R: Gas constant (8.314 J/mol·K)
T: Temperature
n: Electrons transferred
F: Faraday constant (96485 C/mol)
Q: Reaction quotient

Ragone Plot: Energy vs Power Density

Energy Density: 150Wh/kg
Power Density: 300W/kg

Battery Type Comparison

Battery Types

Energy & Power Formulas

Energy Density: Wh/kg = (V × Ah)/kg
Power Density: W/kg = (V × I)/kg

Battery Lifecycle & Degradation

Cycle Count: 0
Capacity Retention: 100%
Coulombic Efficiency: 99.9%

Lifecycle Controls

SEI Formation

Solid Electrolyte Interphase (SEI) forms on the anode surface during first charge. It stabilizes the electrode-electrolyte interface but consumes active lithium.

Battery Safety Mechanisms

Battery Temperature: 25°C
Safety Status: Normal

Safety Controls

Test Scenarios

Protection Mechanisms

Thermal Runaway

Chain reaction of exothermic processes leading to uncontrollable temperature increase. Prevented by multiple safety layers and careful battery management.

What is a Battery?

A battery is an electrochemical device that stores chemical energy and converts it to electrical energy. Lithium-ion batteries use lithium ions as the charge carrier, moving between cathode and anode during charge and discharge cycles.

How Does a Battery Work?

Charging: Li⁺ ions move from cathode (LiCoO₂) to anode (graphite) through the electrolyte, while electrons flow through the external circuit. The ions intercalate into the graphite structure.
Discharging: Li⁺ ions move from anode back to cathode, releasing electrons that power devices. The movement of ions and electrons creates the electrical current.

Key Components

Cathode (+): Typically LiCoO₂, LiFePO₄, or NMC. Releases Li⁺ during charging.
Anode (-): Graphite that accepts Li⁺ during charging and stores them between graphene layers.
Electrolyte: LiPF₆ in organic solvent. Allows Li⁺ ion transport between electrodes.
Separator: Porous polymer membrane. Prevents short circuit while allowing ion flow.

Performance Metrics

Energy Density (Wh/kg): How much energy a battery can store per unit mass.
Power Density (W/kg): How fast a battery can deliver power per unit mass.
Cycle Life: Number of charge/discharge cycles before capacity drops to 80%.
Coulombic Efficiency: Ratio of discharge to charge capacity (typically >99%).

Applications

Consumer Electronics: Smartphones, laptops, tablets require high energy density.
Electric Vehicles: Need both high energy and power density with good cycle life.
Energy Storage: Grid storage requires long cycle life and low cost per kWh.
Power Tools: Demand high power density for rapid discharge.