Lithium battery industry terminology and explanations!

Lithium ion battery: It is a type of battery that uses materials that can undergo lithium ion insertion/extraction reactions as positive and negative electrode active materials, 

and uses organic electrolytes or polymer electrolytes containing lithium salts. 

It is a secondary battery (i.e. rechargeable battery) that mainly relies on the movement of lithium ions between the positive and negative electrodes to function.

Cell: refers to the basic device and unit that directly converts chemical energy into electrical energy, also known as a battery cell. 

It is the basic component that makes up a battery, generating electrical energy through internal chemical reactions.

Lithium cell: A type of battery that uses lithium metal or lithium alloy as the positive/negative electrode material and a non-aqueous electrolyte solution. 

Among them, lithium-ion batteries (LIBs) are the most widely used. 

They do not contain metallic lithium, but use lithium alloy metal oxides as positive electrode materials and graphite as negative electrode materials, 

and achieve lithium ion transport through non-aqueous electrolytes.

Primary cell: A device that generates electric current through redox reactions, 

which converts chemical energy into electrical energy by utilizing the electrode potential difference between electrodes.

Secondary cell: An electrochemical device that can store chemical energy and release electrical energy when necessary. 

It converts electrical energy into chemical energy during charging and stores it, 

and then converts chemical energy into electrical energy during discharging for output.

Fuel cell: A device that directly converts the chemical energy of fuel and oxidant (usually oxygen) into electrical energy through electrochemical reactions. 

This conversion process is not limited by the Carnot cycle, therefore it has a high energy conversion efficiency.

Alkaline cell: A battery that uses a chemical reaction between zinc and manganese dioxide to generate electrical energy. 

It can be a primary or secondary battery.

 The main characteristic of this type of battery is that its electrolyte is alkaline, 

usually using potassium hydroxide (KOH) aqueous solution as the electrolyte, hence the name "alkaline battery".

Dry cell: also known as a primary battery, 

is a type of voltaic battery that uses a certain absorbent (such as sawdust or gelatin) to make its contents into a paste that will not overflow, 

in order to generate direct current.

Solid electrolyte cell: It is a type of battery that uses solid electrolytes instead of traditional liquid electrolytes.

 According to the degree of solidification, solid-state batteries can be divided into semi-solid state batteries and all solid state batteries. 

Semisolid state batteries reduce the amount of electrolyte used on the basis of liquid state batteries and increase the use of composite electrolytes; 

All solid state batteries completely eliminate the original electrolyte and use solid electrolytes, with positive and negative electrodes separated by thin films.

All solid state rechargeable Li ion battery: 

As the name suggests, it refers to a lithium-ion battery in which the electrodes (positive and negative electrodes) and electrolyte are both in solid state. 

This type of battery consists of three parts: positive electrode material, solid electrolyte, and negative electrode material, and does not contain any liquid components. 

The positive electrode is usually made of lithium metal or lithium-ion compounds, while the negative electrode is made of carbon materials or lithium titanate salts. 

Solid electrolytes are composed of inorganic solid materials such as oxides, sulfides, or phosphates.

Gel polymer rechargeable Li ion battery: it is a kind of lithium ion battery that uses gel polymer electrolyte as the ion conduction medium. 

This type of battery is structurally similar to liquid lithium-ion batteries, but the main difference lies in the electrolyte. 

Gel polymer electrolyte is composed of a mixture of polymer and salt, and may add plasticizers and other additives to improve ionic conductivity. 

The electrolyte can be "dry" or "colloidal", most of which are polymer gel electrolytes.

Half solid state Li ion battery: refers to a battery in which one electrode does not contain liquid electrolyte and the other electrode contains liquid electrolyte, 

or where the mass or volume of solid electrolyte in a single cell accounts for half of the total mass or volume of electrolyte in the cell. 

This type of battery combines some of the characteristics of liquid and solid-state batteries, 

retaining the high ionic conductivity of liquid batteries while also possessing the high safety and structural stability of solid-state batteries.

Coin Li ion cell: also known as lithium-ion coin cell or button battery, is a type of battery with small external dimensions, large diameter, and thin thickness. 

The working principle is based on the reversible insertion and extraction of lithium ions between the positive and negative electrodes. 

During charging, lithium ions are deintercalated from the positive electrode material, move to the negative electrode through the electrolyte, 

and embed into the negative electrode material; 

During discharge, lithium ions are released from the negative electrode and return to the positive electrode through the electrolyte, 

while electrons flow from the negative electrode to the positive electrode through an external circuit, generating electrical energy.

Jelly roll: A jelly roll is a tubular structure used to support and protect rolled materials, typically cylindrical or conical in shape.

Cell can: As an important component of a battery, it is mainly used to package and protect the electrolyte and electrodes inside the battery.

Cell lid: It is a cover designed specifically for batteries, whose main function is to protect the internal structure and circuits of the battery, 

prevent external factors such as dust, moisture, or other pollutants from entering the battery, and thus affect the normal operation of the battery. 

It is usually installed on the top or side of the battery to ensure its internal sealing or locking mechanism.

Lid sealing compound: A chemical substance or mixture specifically used to seal the opening of a battery casing. 

Its main functions include protecting the interior of the battery, providing sealing, and enhancing battery safety.

Electrode: It is an experimental equipment used for detecting electrical signals, performing electrical stimulation, and recording nerve cell activity. 

It is widely used in various fields such as biotechnology, medical equipment, electronic products, and automobiles. 

According to their different functions and usage methods, electrode sheets can be divided into various types, 

such as recording electrodes, electrical stimulation electrodes, reference electrodes, grounding electrodes, etc. In addition, according to the different materials and uses, 

electrode sheets can be further divided into various types such as self-adhesive electrode sheets, silicone electrode sheets, 

conductive electrode sheets, non-woven electrode sheets, etc.

Positive electrode: usually refers to an electrode with high potential that contains active substances that undergo reduction reactions during discharge. 

It is a key component used in lithium-ion batteries for storing and releasing lithium ions.

Negative electrode: usually refers to an electrode with high potential that contains active substances that undergo reduction reactions during discharge. 

In a battery, the negative electrode is the end with a lower potential. 

During discharge, the negative electrode releases electrons and accepts lithium ions from the positive electrode.

Ferrous lithium phosphate: It is an electrode material for lithium-ion batteries, with the chemical formula LiFePO4 (LFP). 

It has the advantages of high energy density, high safety, and long lifespan.

Nickel Cobalt Manganese: Nickel cobalt manganese is a key ternary positive electrode material for lithium-ion batteries, 

with the chemical formula LiNixCoyMn1-x-yO2. Having higher specific capacity and lower cost than unit positive electrode materials. 

Lithium cobalt oxide is one of the most widely used battery materials, but cobalt resources are becoming increasingly scarce, expensive, 

and there are safety hazards in the use of lithium cobalt oxide batteries.

Graphite negative electrode material: Due to its excellent conductivity and chemical stability, 

it has become one of the most commonly used negative electrode materials in lithium-ion batteries. 

It can reversibly insert and remove lithium ions, 

thereby achieving the storage and release of electrical energy during the charging and discharging process. 

The crystal structure of graphite is stable, with a large molecular spacing that is compatible with lithium ion insertion and stripping. 

At the same time, its large specific surface area provides a large electrochemical reaction surface, which helps to improve the energy density and power density of batteries.

Hard carbon: Hard carbon is carbon that does not graphitize after high-temperature treatment, and its internal crystal arrangement is disordered with large interlayer spacing. 

This unique structure allows the hard carbon negative electrode to store more charge at the same volume, thereby improving the energy density and endurance of the battery.

Soft carbon: refers to amorphous carbon that can be graphitized under high temperature conditions (usually greater than 2500 ℃). 

Soft carbon materials have lower crystallinity (i.e. graphitization degree) and higher reversible specific capacity, generally greater than 300mAh/g. 

In addition, soft carbon materials also have good compatibility with electrolytes, which helps to improve the cycling stability of batteries.

Tab: It is a metal conductor in a battery that leads positive and negative electrodes from the inside of the battery cell. 

Its shape is similar to an "ear", hence the name. Ji'er is usually composed of a metal strip and a rubber strip. 

The metal strip is used for conductivity, while the rubber strip plays a role in sealing and connecting.

A binder, also known as an adhesive or bonding agent, is a substance that can tightly connect two or more materials together through physical or chemical reactions. 

A mixture typically composed of multiple components, including but not limited to base materials.

Solvent: Battery grade solvent refers to high-purity organic compounds used to prepare electrolyte solutions in batteries. 

As a carrier for electrolytes, solvents can dissolve electrolyte salts and promote ion conduction between the positive and negative electrodes of the battery, 

thereby ensuring the normal operation and performance of the battery.

Conductive agent: A conductive substance added during electrode fabrication to ensure good charge and discharge performance of the electrode. 

It plays a role in collecting microcurrents between active substances and between active substances and current collectors, 

reducing the contact resistance of electrodes, accelerating the movement rate of electrons, 

and effectively improving the migration rate of lithium ions in electrode materials, thereby improving the charging and discharging efficiency of electrodes.

Additive: Lithium battery additives can be classified into various types based on their functions and effects,

 mainly including film-forming additives, functional additives, safety additives, etc.

Film-forming additive

Definition: It is mainly used to form a stable and dense solid electrolyte membrane (SEI) 

on the surface of electrodes to prevent direct contact between electrodes and electrolytes, 

thereby avoiding internal short circuits in batteries.

Common types: such as ethylene carbonate (EC), propylene carbonate (PC), etc.

Functional additives

Definition: Mainly used to improve certain performance of batteries, such as increasing battery capacity, 

improving battery charging and discharging efficiency, and increasing battery cycle life.

Common types include surfactants, rheology agents, particle enhancers, wetting and dispersing agents, etc.

Safety additives

Definition: Mainly used to improve the safety performance of batteries, such as flame retardants, explosion-proof agents, etc.

Common types: such as LiAlO2, LiBOB, LiPF6, etc.

Copper foil: Copper foil for lithium batteries is a metal copper foil produced by electrolysis and surface treated with copper raw materials. 

The thickness is usually below 18 microns, and the most commonly used copper foil is below 12 microns. 

It serves as both a carrier for negative electrode active materials 

and a current collector for negative electrode electron collection and conduction in lithium-ion batteries, 

which has a significant impact on the negative electrode manufacturing process and electrochemical performance of lithium-ion batteries.

Aluminum foil: Lithium ion battery aluminum foil refers to the positive electrode foil of lithium-ion batteries, 

which is a non modified positive electrode foil with a thickness of about 0.01mm, also known as current collector aluminum foil. 

The current collector is one of the core components of lithium batteries, 

whose main function is to collect the current generated by the active material of the battery in order to form a larger current output to the outside, 

while also requiring sufficient contact with the active material. In lithium batteries, 

aluminum foil is often used as a positive electrode current collector due to its excellent conductivity, ductility, and corrosion resistance.

Bottom gasket insulator: As the name suggests, it is a gasket located at the bottom of a lithium battery. 

It is mainly used to fill the gaps inside the battery caused by differences in size and material between components, 

improving the compressibility and safety performance of the battery. 

Specifically, the functions of lithium battery bottom gaskets mainly include sealing, isolation, fixing, and shock absorption.

Tape: It is a widely used pressure-sensitive tape in the intermediate production process of lithium battery cells, 

such as winding/laminating, shell welding, and sealing. 

Its main function is to insulate, fix lithium battery components, and protect various parts inside the battery.

Center pin: It is an important component inside a lithium battery, located at the center of the battery, 

used to connect the positive and negative poles of the battery and serve as a channel for current transmission. 

Its main functions include current transmission, structural support, and thermal management.