CATHODE

Question 1

TermManufacturing process of cathode materials

Answer 1

Definition

Question 2

Cathode materials, a critical element that decides a battery capacity and life

Answer 2

Question 3

Cathode Active Material (CAM)

Answer 3

The primary lithium host for electrochemical reactions in the cathode; typically a lithium transition metal oxide.

Question 4

Transition Metal Oxide

valence intercalations

Answer 4

Class of compounds (e.g. LCO, NMC) used as main cathode materials for their multi-valence lithium intercalation ability.

Question 5

Intercalation Compound

Answer 5

Structure that allows reversible insertion/removal of lithium ions (typical cathode behavior).

Question 6

Layered Structure

cobaLt

Answer 6

Crystal arrangement with lithium and transition metal oxide layers (found in LCO, NMC, NCA).

Question 7

Spinel Structure

3d manganese

Answer 7

3D interconnected oxide lattice (e.g., LMO) that improves power output and stability. AB₂X₄, where A and B are cations and X is an anion

Question 8

Olivine Structure

iron thermal chemical

Answer 8

Robust phosphate crystal (e.g., LFP) with high thermal and chemical stability.

On the left, the spinel structure of LMO and on the right, that of the olivine LFP. The yellow spheres represent Li ions in the structures.

Question 9

Disordered Rocksalt

capacity and safe

Answer 9

Novel crystal structure enabling high capacity and improved safety without traditional layered order.

Question 10

Polyanion Cathode

PiSS

Answer 10

Cathode containing phosphate, silicate, or sulfate, adding stability and safety.

Question 11

Lithium Content

Answer 11

Amount of lithium stored in cathode structure, impacts battery capacity.

Question 12

Stoichiometry

Answer 12

Ratio of atoms in the cathode material; correct Li:TM (transition metal) balance critical for performance.

Question 13

Cobalt Content

ED and Stability

Answer 13

The percentage of cobalt in a cathode; reduces cost as cobalt is minimized or replaced.

Question 14

NiCkEl Enrichment

energy and cost

Answer 14

Use of higher Ni fractions in NMC/NCA to boost energy density and reduce cost.

Question 15

Dopant

pscOND MATe MT

Answer 15

Element intentionally added in small quantities to enhance cathode performance, stability, or conductivity. tantilum molybedum

(Mg, Ti, Al, Ta, Mo)

Question 16

Conductive Additive

Answer 16

Carbon black, graphite, or other particles mixed to improve electron flow through cathode.

Question 17

Aluminum Foil

Answer 17

Used as the current collector for cathodes; lightweight, corrosion-resistant, high conductivity.

solid wire thin metal

Question 18

Cathode Binder

pvdf and sbr

Answer 18

Polymer such as PVDF or SBR; holds active particles on current collector.

Question 19

Surface Coating

Alumina

Answer 19

Process of covering cathode particles (e.g., with alumina) to improve cycle life and stability.

Question 20

Morphology Control

Answer 20

Tuning particle size and shape for better ion diffusion and rate capability.

Question 21

Particle Size Distribution

CONDUC PACK KINEC

Answer 21

The spread of sizes of cathode granules, affecting conductivity, packing, and reaction kinetics.

Question 22

Porosity

P VS PACKING

Answer 22

Percentage of void space in electrode; higher porosity improves ion transport but can decrease packing density.

Question 23

Cathode Slurry

PBS ADDITIVIE

Answer 23

Homogeneous mix of cathode powder, binder, solvent, and additive for film coating.

Question 24

Cathode Film

“Thin Films Boost Energy Safely”

Answer 24

Resulting active layer formed on aluminum collector, controlling active capacity. Mnemonic for Cathode Film Properties
“Thin Films Boost Energy Safely”
Thin – Thin layer, micron-scale thickness
Films – Deposited by film techniques (PLD, sputtering, etc.)

Boost – Increased energy density and output
Energy – High electrochemical performance from pure active material
Safely – Safer configuration (solid-state, no flammable electrolyte)

Question 25

Drying Oven | solvent

Answer 25

Used to remove solvent from freshly cast cathode coatings.

Question 26

Calendering (Cathode)

Answer 26

Compressing the cathode film to the desired density for better electrode contact.

Question 27

Crack Propagation

Answer 27

The tendency for cracks to form/grow in the cathode, a root cause of aging.

Question 28

Intergranular Cracking | 2nd Ni

Answer 28

Cracking between cathode secondary particles, reducing cycle life in high-Ni materials.

Question 29

Secondary Particle | large granules

Answer 29

Larger granules made up of primary particles aggregated for better packing and conductivity.

Question 30

Primary Particle

Answer 30

The smallest, individual crystal unit used in cathode structure.

Question 31

Microstructure | GRAIN PHASE AND VOID

Answer 31

Arrangement of grains, voids, and phases inside the cathode, which governs electrochemical performance.

Question 32

Gradient Cathode | gradual csp

Answer 32

A gradient cathode in lithium-ion batteries is an advanced cathode material engineered to have a gradual change (gradient) in composition, structure, or porosity from the core (center) to the surface of each particle. This intentional variation can be in the concentration of transition metals like nickel, manganese, cobalt, or in structural properties like porosity and particle ordering.

Question 33

Core-Shell Structure | #HEAT

Answer 33

Cathode particle with different core and shell chemistries to optimize cycling and thermal stability.

Question 34

Single Crystal Cathode

Answer 34

Particles made of a single, continuous crystal, enhancing fracture resistance and cycle life.

Question 35

Polycrystalline Cathode

Answer 35

Particles composed of many smaller crystals, more cost-effective but can crack more easily.

Question 36

Cation Mixing | Crystal not layered oxides

Answer 36

Mixing of lithium and transition metals in crystal lattice; generally undesirable in layered oxides.

Question 37

Oxygen Vacancy | 3 C's

Answer 37

Absence of oxygen atom in the lattice, affects capacity, conductivity, and cycling.

Question 38

Cathode Capacity (mAh/g)

Answer 38

The theoretical/actual amount of charge the cathode can hold per gram.

Question 39

Initial Irreversible Capacity Loss

Answer 39

First-cycle capacity loss due to side reactions and SEI formation.

Question 40

Rate Capability (Cathode)

Answer 40

Cathode’s ability to deliver or accept charge under high current.

Question 41

Fast Charge Performance

Answer 41

How strongly the cathode performance degrades under rapid charging.

Question 42

Voltage Fade | Mn

Answer 42

Decline in average discharge voltage during repeated cycling, often in Mn-rich cathodes.

Question 43

Lattice Strain | cycle

Answer 43

Mechanical stress in cathode lattice during cycling, often leading to cracking.

Question 44

Phase Transformation | cycle

Answer 44

Change in crystal structure during cycling, which can cause degradation.

Question 45

High-Voltage Cathode

Answer 45

Cathode material that safely operates at voltages above 4.2V, boosting energy density but increasing stress.

Question 46

Thermal Stability (Cathode) | heat

Answer 46

Resistance of cathode to heat and runaway exothermic reactions. ## Footnote Battery Example: When discharging, the chemical reactions in the battery release energy as both electricity and heat—making the process exothermic. Thermal Runaway: In lithium-ion batteries, a dangerous cycle of exothermic reactions can cause rapid temperature rise, further accelerating heat release and potentially leading to fires or explosions. Stages: Exothermic reactions in batteries include decomposition of the electrolyte, separator melting, and cathode decomposition, all of which release significant heat.

Question 47

Oxygen Evolution

Answer 47

Loss of oxygen from the crystal lattice at high voltages, causing safety issues and degradation.

Question 48

Solubility (Cathode) | DisolvE

Answer 48

Tendency of active material to dissolve into electrolyte, can result in transition metal loss and self-discharge.

Question 49

Cathode Manufacturing Cost

Answer 49

Sum of raw materials, energy, labor, process yield, and quality control costs for cathode production.

Question 50

Precursor Cost

Answer 50

Price of metal salts and chemicals used in the synthesis of cathode active materials.

Question 51

Purity Specification

Answer 51

Degree to which metals and precursors must be free of impurities for battery grade use.

Question 52

Supply Chain Security (Cathode)

Answer 52

Reliability and geopolitical risk associated with raw and processed cathode materials.

Question 53

Recycling Content

Answer 53

Proportion of recycled metals/oxides blended into new cathode for cost/environmental benefit.