Technology › Lithium-ion

Lithium-ion technology

From cathode chemistry to pack design: the components, the control electronics and the thermal behaviour that decide performance and safety.

How to use this cluster

Read the cluster in the order a pack is designed: chemistry first, then cell format, then thermal behaviour, then the BMS. Changing chemistry after the pack architecture is fixed is expensive, and changing the BMS after the enclosure is fixed is worse. The articles below follow that sequence and cross-link when a decision in one layer constrains another.

The four decisions in a lithium pack

Chemistry. LFP favours cycle life and safety; NMC favours energy density; LTO favours power and low-temperature behaviour at a cost in energy. The chemistry sets the voltage window and the thermal risk.
Cell format. Prismatic cells simplify packing; cylindrical cells are mature and cost-effective; pouch cells save space but need mechanical support. The format drives the assembly process and the failure mode.
Thermal design. Air cooling is adequate at low C-rates; liquid cooling is needed for fast charge and high ambient temperature. The thermal path decides how long the pack lasts, not just how safe it is.
BMS. Passive balancing is sufficient for well-matched cells; active balancing helps large or second-life packs. The BMS must speak the protocol of the charger and inverter around it.

What this cluster does not cover

Certification, transport rules and application sizing are separate clusters. Use the safety and transport pillar for UN38.3 and modal rules, the applications hub for duty-cycle fit, and the testing site for the standards behind a performance claim.

Topic	What it covers
Cathode & anode	LFP/NMC/NCA cathodes and graphite/silicon anodes
Cathode materials	NMC, NCA, LFP and the cobalt question
Anode materials	Graphite, silicon and the trade-offs
Graphite anode	Natural vs synthetic graphite and performance
LCO cathode	Lithium cobalt oxide and its niche
LMFP cathode	Manganese-doped LFP and energy density
Electrolyte & separator	Salt, solvent, separator and safety
BMS technology	Sensing, protection and state estimation
Cell balancing	Passive vs active balancing
Thermal management	Cooling, heating and runaway propagation
Cell, module, pack	How cells become a pack
Pack design	Mechanical, electrical and service design
Lithium manufacturing	Electrode coating to formation
Electrode process	Coating, drying, calendering and slitting

Where the cost sits

The cell is the largest cost, but the BMS, thermal hardware and enclosure decide whether the pack survives. A cheaper cell with an undersized BMS is not a cheaper pack; it is a shorter-lived one. Compare the bill of materials, not only the cell price.

Frequently asked questions

Which chemistry should I start with?

Start with the duty cycle and the temperature window. LFP is the default for stationary and cost-sensitive cycling; NMC is chosen when energy density or cold performance matters more than cycle life; LTO is a niche for high power and very low temperature.

Do I need a BMS for a small pack?

Yes. Every lithium pack needs cell-level protection against overcharge, over-discharge and over-temperature. A small pack can use a simpler BMS, but it cannot safely omit one.