Before diving into performance metrics, compliance, or pack design, it’s essential to master the core concepts of lithium batteries—from chemistry to cell structure.
Whether you’re sourcing batteries for e-bikes, solar systems, or medical devices, understanding the basics helps you avoid common selection errors, communicate with engineers, and make informed decisions.
This page walks you through the core knowledge every professional buyer, engineer, or project manager should know, including battery types, cell structure, material composition, key terms, and typical misunderstandings. No deep BMS theory or testing protocols here—just the essential groundwork.
A lithium battery is a rechargeable energy storage device that uses lithium ions to move between the anode and cathode during charge and discharge cycles. It’s known for high energy density, low self-discharge, and long cycle life.
The three main types are cylindrical cells, prismatic cells, and pouch cells. Each type differs in structure, energy density, and suitability for specific applications like e-bikes, power tools, or storage systems.
Core materials include a positive electrode (cathode), negative electrode (anode), separator, electrolyte, and current collectors. These parts work together to enable the flow of lithium ions during operation.
Lithium ions move from the anode to the cathode during discharge and reverse during charging. This electrochemical process allows the battery to store and release energy efficiently.
Li-ion batteries have higher energy density but lower thermal stability. LiFePO₄ offers longer cycle life and greater safety, making it ideal for applications requiring high reliability.
Cylindrical cells offer excellent mechanical stability, efficient heat dissipation, and mature production processes. They’re commonly used in power tools, e-bikes, and energy storage packs.
Yes—when properly designed with quality materials and BMS protection. Certifications like UN38.3, CE, and UL also help ensure compliance and safety for transport and use.
Absolutely. Battery packs can be tailored with different cell formats, capacities, and configurations depending on your voltage, current, and space requirements.
A lithium battery is a device that stores electrical energy using lithium metal or lithium compounds. Understanding what a lithium battery cell is made of helps buyers assess whether a specific chemistry matches their application’s needs.
Broadly speaking, lithium batteries come in two categories:
Primary lithium batteries – Non-rechargeable, used in low-power devices.
Secondary lithium batteries – Rechargeable, including Li-ion and LiFePO₄ types. The difference between Li-ion and LiFePO4 lies in energy density, safety, and cycle life, making them suitable for different markets like EVs or solar storage.
ithium battery technology began in the 1970s. Sony introduced the first commercial lithium-ion battery in 1991. Today, lithium batteries are widely used in electric vehicles, energy storage, and consumer electronics.
Key Milestones:
1970s: First lithium metal batteries
1991: Sony launches Li-ion
2005–2020: Rise of EV and portable tech
2020+: Fast charging, solid-state innovation
Every battery pack is built from cells, and understanding their internal structure is key to understanding performance, safety, and lifespan.
Core components include:
Cathode (positive electrode) – Typically NCM, NCA, or LiFePO₄ materials.
Anode (negative electrode) – Usually graphite or lithium titanate (LTO).
Electrolyte – A liquid medium allowing lithium ions to move between electrodes.
Separator – A microporous film that prevents short circuits but lets ions pass through.
Shell/Casing – Determines the shape and some thermal behavior of the cell.
If you’re looking for common lithium battery types for e-bikes, you’ll likely encounter NCM, NCA, and LiFePO₄. Each type balances trade-offs between cost, energy output, charging speed, and safety.
| Cathode Material | Voltage | Energy Density | Charge/Discharge Performance | Cycle Life | Thermal Stability | Applications |
|---|---|---|---|---|---|---|
| Lithium Cobalt Oxide (LiCoO2) | Nominal 3.6V (Range 3.0–4.2V) | 150–240 Wh/kg | 0.7–1C, Max 2.5C, >1C shortens lifespan | 500–1000 (at standard depth of discharge) | 150°C (302°F): risk of thermal runaway | Phones, tablets, laptops, cameras, drones |
| Ternary Material (LiNiCoMnO2) | Nominal 3.7V (Range 3.0–4.2V) | 150–220 Wh/kg | 0.7–1C, Max 2.5–5C, 10C: 3.0Ah cell ~15s | 1000–2000 (at standard depth of discharge) | 210°C (410°F): stable | E-bikes, power tools, EVs, medical, industrial |
| Lithium Manganese Oxide (LiMn2O4) | Nominal 3.7V (Range 3.0–4.2V) | 100–150 Wh/kg | 0.5–1C, Max 2.5C, 10C: 3.0Ah cell ~15s | 300–700 (at standard depth of discharge) | 250°C (482°F): stable | EVs, power tools, low-cost equipment, seasonal storage |
| Lithium Iron Phosphate (LiFePO4) | Nominal 3.2V (Range 2.5–3.65V) | 90–120 Wh/kg | 1C typical, up to 30C (5s burst), fast charge/discharge | 2000+ (at standard depth of discharge) | 270°C (518°F): excellent stability | Energy storage systems, EVs, medical, industrial |
| Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2) | Nominal 3.6V (Range 3.0–4.2V) | 200–260 Wh/kg | 1C typical, Max 5C, charge cut-off voltage 4.2V | 500 (at standard depth of discharge) | 150°C (302°F): stable | High-energy EVs, drones, aerospace |
| Lithium Titanate (Li4Ti5O12) | Nominal 2.4V (Range 1.8–2.85V) | 50–80 Wh/kg | 1C typical, Max 5C, charge cut-off voltage 2.85V | 3000–7000 | Stable under 300°C (572°F) | UPS, power backup, solar storage, base station batteries |
Another point often misunderstood is the battery structure vs battery pack. A battery cell is a single energy unit, while a pack is a structured combination of cells plus BMS, wiring, and casing. Choosing the right structure depends on your form factor and power needs.
Cylindrical cells (e.g., 18650, 21700) – Highly standardized and mechanically robust.
Prismatic cells – Boxy format, easier for space-efficient pack design.
Pouch cells – Lightweight and compact, often used in consumer electronics.
Each format has unique trade-offs between energy density, durability, and manufacturability.
Learning how to read lithium battery specifications like voltage, capacity, and C-rate is essential for comparing suppliers. For example, energy (Wh) is calculated as voltage × capacity, while discharge rate (C rating) helps determine load capability.
Voltage (V) – Nominal voltage depends on chemistry (3.2V for LFP, 3.7V for NCM/NCA).
Capacity (mAh or Ah) – Indicates how much charge a battery can store.
Energy (Wh) – Calculated as Voltage × Capacity. Defines usable output.
Discharge Rate (C Rating) – The speed at which energy is released. 1C means full discharge in 1 hour.
Cycle Life – Number of full charge/discharge cycles before capacity drops below 80%.
Battery performance is tightly linked to the materials used in each part of the cell.
| Term | Definition |
|---|---|
| SOC | State of Charge – Current battery energy percentage |
| DOD | Depth of Discharge – How much energy is removed per cycle |
| BMS | Battery Management System – Protects and monitors the battery |
| Cycle Life | Number of full charge-discharge cycles |
| Self-discharge | Natural energy loss over time when idle |
Battery performance is tightly linked to the materials used in each part of the cell.
| Component | Material | Function |
|---|---|---|
| Cathode | NCM / NCA / LFP | Stores lithium ions; affects energy & safety |
| Anode | Graphite / LTO | Releases lithium ions during discharge |
| Electrolyte | Organic solvent + lithium salt | Medium for ion transfer |
| Separator | Microporous polyethylene or polypropylene | Prevents short circuit, allows ion flow |
Not always. You must balance size, discharge rate, and weight constraints.
Different chemistries serve very different purposes.
Without BMS, lithium batteries can overheat, swell, or even catch fire.
By understanding what lithium batteries are made of, how they function, and how different chemistries compare, you’re now better prepared to read specs, compare suppliers, and make informed buying decisions. This chapter lays the groundwork for exploring advanced topics like battery pack design, thermal management, BMS architecture, and international certification in future sections.
Need a custom lithium battery pack? Just send us your specs—we’ll help you choose the right voltage, case, and configuration for your application.
At JUNDA, we make customization easy. Follow these 3 simple steps to start today:
Send your battery requirements — voltage, capacity, casing type, or upload drawings/photos.
We’ll evaluate your specs and recommend the best configuration. A detailed quote will be sent within 24 hours.
After approval and deposit, we start production. Shipping and tracking will be arranged for fast, secure delivery.
