Battery Chemistry Definitions & Glossary

Battery Chemistry Definitions & Glossary has quite a lot of overlap with the Cell Glossary. Hence apologies for any repeats, although some are required.

Ah – Ampere-hour is the unit of cell capacity.


Anode Free – a battery cell where the Anode is formed during the cell formation cycles.

Button Cell

Calendar Ageing – the capacity loss of the battery with time and without cycling.

Calendaring –

Capacity – battery capacity is expressed in ampere-hours.


Charge – the process of electrical energy being converted into chemical energy.

Coating –

Coin Cell –

Coulomb – unit of electric charge. One coulomb (1C) equals one ampere-second (1As).

C rate – the Ampere current in charge or discharge divided by the Ah capacity of the cell.

Cycle Ageing – the capacity loss in a battery through charge and discharge repeated cycling.

Cycle Life

Discharge – the process of chemical energy being converted into electrical energy.

Dry Room –

EL Cell



Formation –


Humidity –

LCA – Life Cycle Analysis

LFP – Lithium Iron Phosphate, a lithium ion cathode material with graphite used as the anode. This cell chemistry is typically lower energy density than NMC or NCA, but is also seen as being safer.

Instrumenting Cells – if you are going to instrument a cell you need to be able to do this reliably and robustly. The process flow diagram illustrates the experimental stages employed for cell instrumentation and includes: sensor fabrication, cell modification and sensor insertion. The diagram highlights the different verification stages for assessing LIB performance, operation and ageing.
WMG Smart Cell instrumentation

LMFP – Lithium managanese iron phosphate.

M3PCATL’s trade name for their own developed variation on LFP.

Na Ion – Sodium Ion battery cell.

Negative Electrode

NMC – Lithium Nickel Manganese Cobalt Oxides are a family of mixed metal oxides of lithium, nickel, manganese and cobalt. Nickel is known for its high specific energy, but poor stability. Manganese has low specific energy but offers the ability to form spinel structures that allow low internal resistance.

typical OCV vs SoC
Open Circuit Voltage (OCV) – is the potential difference between the positive and negative terminals when no current flows and the cell is at rest.

PbA – abbreviation of lead acid battery.

Positive Electrode

Primary Cell – a cell that can only be discharged once.

Secondary Cell – a rehcargeable battery cell.

Self Discharge

Separator – material that separates the anode and cathode electrically whilst allowing ions to pass through.

Solid Electrolyte Interphase – is formed on electrode surfaces from decomposition products of electrolytes. The SEI allows Li+ transport and blocks electrons in order to prevent further electrolyte decomposition and ensure continued electrochemical reactions.

Solid State – anode, cathode and electrolyte are solid.

Third Electrode – electrode used in cells to establish the potential of the anode and cathode independently.