Lithium-ion battery is a type of rechargeable battery where the ions move from negative electrodes to the positive electrode during discharge and come back upon charging. Li-ion batteries are commonly used in home electronics which require high energy density, tiny memory effect and low self-discharge. Li-ion batteries are being widely adopted in electric vehicles, grid level energy storage solutions and for military as well as aerospace applications. Moreover, lithium-ion batteries have become a constant replacement for the lead–acid batteries.

Composition of Lithium-ion Batteries

Li-ion batteries are composed of four main components namely cathode, anode, electrolyte, and separator. Lithium-ion battery generates electricity because of continuous reactions of lithium.

Cathode

A cathode determines the capacity and voltage of a Li-ion battery. The cathode of a Li-ion battery is lithium oxide, since lithium is unstable in the element form.

A thin aluminium foil holds the frame of the cathode, which is coated with a compound made up of active material, conductive additive and a binder. The active material contains lithium ions, the conductive additive is added to increase conductivity and the binder acts as an adhesive which aids the active material as well as the conductive additive to settle on the aluminium substrate.

Cathode plays an important role in determining the characteristics of the battery as the capacity and voltage are determined by the type of active material used for cathode. The higher the amount of lithium, bigger the capacity and the potential difference between cathode and anode, and higher is the voltage. The potential difference is small for anode depending on their type. The potential difference for cathode is generally higher and it plays a significant role in determining the voltage of the battery.

Anode

The anode is also coated with an active material that enables the flow of electric current through the external circuit while also allowing the reversible absorption or emission of lithium ions that are released from the cathode.

When the battery is being charged, lithium ions get stored in the anode and not the cathode. When the conducting wire connects the cathode to the anode in the discharge state, lithium ions flow back to the cathode through the electrolyte, and the electrons get separated from lithium ions and move along the wire generating electricity.

 Graphite is used for an anode as it has a stable structure. It’s properties such as structural stability, low electrochemical reactivity, storage of lithium ions and lower price lead to the wide use of the material for anode.

The anode is also coated with active material, conductive additive and a binder.

Electrolyte

Electrolyte is a major component of a Li-Ion Battery as it facilitates the movement of the lithium ions between the cathode and the anode and the electrons move through the wire. An electrolyte is generally composed of chemicals with high ionic conductivity to facilitate the movement of lithium ions.

The electrolyte is composed of salts which enable the passage for lithium ions, the solvents that are organic liquids which dissolve the salts, and additives which are added in small amounts and have specific functions. The speed of lithium ions also depends on the type of electrolytes used. High purity electrolytes are a core component of li-ion batteries. The most commonly used electrolyte comprises of lithium salt, such as lithium hexafluorophosphate in an organic solution.

Separator

While the cathode and anode determine the basic performance of a battery, electrolyte and separator determine the safety of a battery. The separator acts as a physical barrier by keeping the cathode and anode apart. It also prevents the direct flow of electrons and allows only the lithium ions to pass through the internal microscopic hole. Commercialized separators used are generally synthetic resins like polyethylene (PE) and polypropylene (PP).

Every single component of a Li-ion battery is essential as the battery cannot function in the absence of any.

Advantage of Lithium-Ion Batteries:

· Lighter Design: Li-ion batteries are lighter as compared to other rechargeable batteries considering the battery capacity and are thus used in portable consumer electronic devices where weight and form factor are the important selling points.

· High energy density: Li-ion batteries have a higher energy density when compared to other rechargeable batteries. Li-ion Batteries have high power capacity without being too bulky. Lithium ion batteries are thus used in electronic equipment like mobile phones and laptops, which need to operate longer between charges while consuming more power and need batteries with a much higher energy density. Additionally, electric vehicles also run on Li-ion batteries.

· Low self-discharge and longer shelf life: Li-ion battery has lower self-discharge rate as compared to other rechargeable batteries, about 1.5 percent per month which enables longer shelf life when not in use as it discharges slowly than other rechargeable batteries.

· Lower memory effect: Memory effect refers to as the process of losing maximum energy capacity of rechargeable batteries due to repeated recharges after being only partially discharged. Li-ion battery has a minimal memory effect, while other rechargeable batteries like nickel-metal hydride have a very high memory effect.

· Quick charging: Lithium-ion batteries take lesser time to charge as compared to other rechargeable batteries like lead acid, nickel-metal hydride, and nickel-  cadmium.

· Longer lifespan: Li-ion batteries have a longer life span as compared to others. Some lithium ion batteries lose 30 percent of their capacity after 1000 cycles while advanced lithium ion batteries have better capacity even after 5000 cycles.

· Low maintenance: Li-ion batteries do not require maintenance to ensure their performance at optimal level.

· High open-circuit voltage: Li-ion batteries exhibit higher open-circuit voltage due to their chemistry when compared to other batteries such as lead acid, nickel-metal hydride, and nickel-cadmium.

Different Shapes of Lithium-batteries

· Cylindrical: The cylindrical lithium batteries have high specific energy and good mechanical stability. The design allows added safety features, cycles well, offers a long calendar life and is low cost, but it has less than ideal packaging density. It is commonly used for portable applications.

· Prismatic: Prismatic batteries are encased in aluminium or steel for stability. Jelly-rolled or stacked, it is space-efficient but is more expensive to manufacture than the cylindrical battery. They are generally used in the electric powertrain and energy storage systems.

· Pouch: Pouch shaped lithium battery uses laminated architecture in a bag. It is light and cost-effective but exposure to humidity and high temperature can shorten its life. Adding a light stack pressure prolongs longevity by preventing delamination.

Charging and Discharging of Lithium-ion Batteries

Constant Current Phase: In this phase, the charger applies a consistent current to the battery at a relentlessly expanding voltage until the voltage limit per cell is reached.

Balance Phase: In the balance phase, the charger decreases the charging current while the condition of charge of individual cells is conveyed to a similar level by an adjusting circuit, until the point when the battery is adjusted.

Constant Voltage Phase: In the constant voltage phase, the charger applies a voltage equivalent to the greatest cell voltage times the quantity of cells in arrangement to the battery, as the current gradually decays towards 0, until the point when the current is beneath a set edge of around 3% of introductory steady charge current.

Different Voltages of various Lithium-ion variants available in the market:

Lithium cobalt oxide (LCO or LiCoO2): Lithium cobalt oxide is a chemical compound used in positive electrodes of lithium-ion batteries. It consists of layers of lithium that lie between slabs of octahedral structure formed by cobalt and oxygen atoms. It offers high energy density but presents safety risks when damaged. The performance of LiCoO2 in batteries is related with the particle size of the material and different sizes ranging from nanometre to micrometre sized particles are researched and produced. The drawback of Li-cobalt is a relatively short life span, low thermal stability and limited load capabilities. Li-cobalt should not be charged and discharged at a current higher than its C-rating. This implies an 18650 cell with 2,400mAh must be charged and released at 2,400mA.

Lithium iron phosphate (LFP or LiFePO4): It is an inorganic compound and is either a grey, brown, red or black solid which is insoluble in water. LFP batteries have an operating voltage of 3.3 V, charge density of 170mAh/g, long cycle life and stability at high temperatures.

Lithium-Ion Manganese Oxide (LMO or MnO2): Lithium manganese oxide batteries have manganese oxide in their cathodes. They come in many widespread lithium sizes.

Lithium Nickel Cobalt Aluminium Oxide (NCA or LiNiCoAlO2): It shares similarities with nickel manganese cobalt oxide (NMC), which offers high specific energy and long-life span. This is a further development of the lithium nickel oxide.

Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2 or NMC): It is one of the most successful Li-ion systems and has a cathode combination of nickel-manganese-cobalt. These systems can be tailored to serve as Power or Energy cells. Nickel is recognized for its high energy, but poor stability and manganese has the advantage of forming a spinel structure to attain low internal resistance but offers a low energy. Combining the metals improves each other’s strengths.

Lithium titanate (Li4Ti5O12 or LTO): Li-titanate has a nominal cell voltage of 2.40V. It can be fast charged and delivers a high discharge current of about 10 times the rated capacity. It has low-temperature discharge characteristics and is safe.

Manufacturing Process: The manufacture of electrodes, cells and modules/packs for large-format power batteries is still in its early stages. The battery fabricating operation needs to end up noticeably speedier and must be more affordable if lithium-ion energy storage technology is to build up itself effectively in the objective markets. 

Equipment required for the manufacturing of Li-ion Batteries:

Companies, like Hitachi High Technologies, offer Li-ion battery assembly machines at different prices and with different production capacities, that can produce up to 1-2 million pieces per month. These machines have different features:

 Metal welding and joining: Laser welding, resistance welding, ultrasonic welding, soldering, friction-stir welding

Crimping: Can sealing, fluting, safety valve assembly, crimping

Liquid injection and application: Vacuum pressure liquid injection, application of grease etc.

Paste Mixing Machines: The essential raw materials utilized as a part of paste blending are lead sub-oxide, sulphuric corrosive and DI water along with added substances and fasteners in predefined amounts.

Grid Casting Machines: The process of manufacturing positive and negative grids by melting lead at some specific temperature and poring it into moulds is done with the help of grid casting machine.

Pasting: To form pasted plates, the paste of the active material is applied over the grid.

Curing and drying: The pasted plates are then cured and dried to enhance the attachment and bond of the dynamic material to the framework.

Cell assembly Machine: This procedure includes presenting the plates to steam and along these lines drying in a broiler.

Buffing Machine: The positive and negative plate carriers are buffed by methods of a round wire brush turning at a high speed. Buffing is done to expel the oxide layer shaped over the plate.

Wrapping Machine: Both positive and negative plates are gathered then again in a gathering box alongside the separator and base top (for the negative plates). The quantity of positive and negative plates amassed relies upon battery AH limit.

Group burning Machine: This machine helps in the process of melting and joining the top portion of the lugs. All negative plates are welded together to form the negative terminal and all positive plates are welded together to form the positive terminal.

Heat sealing Machine: A heat sealing machine is used to join the container and the lids by melting process.

Terminal assembly Machine: is the process tightening of the terminal nut to the required torque is done which are identified with red colour for the positive terminal and black for the negative.

Leak testing Machines: At various joints, Sealed cells are then tested to detect any leaks.

Acid filling Machine: Using this machine the electrolyte filling is done by adding sulphuric acid into the cell before carrying out the initial charging.

Battery assembly Machine: The cells are then washed, which are stacked as per the general arrangement drawing. The final inspection is then carried out.

Battery charging Machines: In this process, the batteries are moved to water cooled charging inlets for mechanical charging. These batteries are then connected to fully automatic battery chargers and are charged in a three-step charging procedure.

Battery washing and drying Machines: Through a battery washer and dryer machines the charged batteries are taken by automatic conveyors.

Some of the Battery Machine making Manufacturers:

There are numerous battery making machine manufacturers operating globally, who can help in the setting up a manufacturing unit of batteries. Some of them are:

Sovema Group: The company designs equipment’s for both small pilot lines and large automated and integrated manufacturing plants. The company provides equipment’s for cell making, formation and ageing, module assembly, battery pack assembly

Contact Details:

Via Spagna, 13, 37069 Villafranca di Verona – ITALY

Tel. (+39) 045 6335711

BITRODE Corporation: The company is an in-house machines provider to a battery manufacturer present globally. Battery manufacturers and developers around the globe rely on Bitrode Corporation for innovative energy storage solutions.

Contact Details:

Bitrode Corporation:

+1.636.343.6112

9787 Green Park Industrial Drive

St. Louis, MO 63123

Hitachi High-tech: The company offers supply system solutions for assembly of batteries.

Contact Details:

24-14, Nishi-Shimbashi 1-chome, Minato-ku, Tokyo, 105-8717,

Japan

TEL +81-3-3504-7111

Overview of lithium-ion battery production:

Plant Size: The size of the plant relies upon the volume of business we need to do, the quantum of assets we have available to us, and the turnover target we intend to accomplish. For an instance:

· Samsung SDI constructed its Li-ion Battery manufacturing plant which is scheduled to open in second quarter of 2018 in Hungary. Sitting on a 330,000 square-meter site, the plant can produce batteries for 50,000 electric vehicles annually.

· Panasonic Automotive Energy Dalian Co., Ltd. Opens New Automotive Lithium-ion Battery Factory in China in April 2017. The plant has Site area of Approx. 170,000 m², Floor area of Approx. 80,000 m² and the company has invested around $ 42.46 Million.

· AMCO Saft, the world’s leading designer and manufacturer of high-tech industrial batteries has it manufacturing unit in Bangalore. The plant has site area of approx. 75,000 sq. ft.

Therefore, the minimum area required for a Li-ion manufacturing unit is around 70,000 sq. ft.

Production Line: Elements are already mentioned above that we require for establishing the manufacturing unit. Process can be semi-automatic/manual or automatic, automatic production line is quite expensive. For initial stage, semi-automatic/manual production line is suggested.

Machine Maintenance: Most of the machines come with manuals and instructions of their maintenance which is useful to carry out minor repair work. Usually, the after sales services are provided by the machine manufacturers and imported machines are serviced by authorised distributors. Generally, the maintenance cost can add up to 10-20 percent of the total machines’ cost.

Certification Requirement: Before setting a manufacturing plant, stringent pollution control measures should be executed. There are a few affirmations one should obtain before setting out on assembling which includes:

·  IEC/IS product and ISO certification

·  electricity boards

·  certification from Pollution Control Board (PCB)

·  industrial manufacturing licence

·  labour commissioner

·  local authorities

Total Expenditure:  The major cost comes out to be that of the raw material which accounts for about 50-60% of the total expenditure. Energy cost depends upon the country we are targeting, as every country has different energy cost. According to our investigation, depending on the factory’s design and production process, the energy consumption could range from 0.55 to 0.68 Ah.  The core energy consumption are equipment’s/machines, drying room, vacuum dryers. The overall expenditure cost can be divided on the given approximation and can vary country to country:

Trends:

· Widespread Adoption of Lithium-Air Battery: Lithium-air batteries are being widely adopted across different end-use industries as they possess great potential. These batteries can provide up to five times more energy than the lithium-ion batteries. It is anticipated that Li-Air batteries will possibly be rechargeable up to 1,000 watt-hours per kilogram, and all it will need is oxygen. Such a battery could be used to fuel electric automobiles and store the electricity generated by solar panels and wind turbines in the coming years.

· Transparent Lithium-ion Battery: Flexible, transparent lithium-ion batteries have been developed by scientists that could enable in moving towards see-through electronic gadgets like translucent phones and iPads.

· Increasing Power Density of Lithium-Ion Batteries: With the increasing demand for smartphones, electric vehicles, and renewable energy continues to rise, scientists have been constantly trying to improve lithium-ion batteries. Scientists have found out that the use of a modified and engineered form of iron trifluoride as cathode material could triple the energy density of lithium-ion battery electrodes. Reducing cost and increasing energy density are two barriers for widespread application of lithium-ion batteries in electric vehicles.

· Increasing Penetration of Electric Vehicles: As the electric vehicles run on the lithium-ion batteries, the widespread adoption of electric vehicle is anticipated to raise the demand for lithium-ion batteries.

Conclusion:

The exponential growth in the use of electric vehicles and portable electronic devices have created massive interest in compact, inexpensive and light-weight batteries. To fulfil this need, lithium-ion battery is one of the most pleasing technology. The lithium-ion battery market is projected to grow at a CAGR of 18.6% in India over the next five years. Factors such as growing demand for lithium-ion batteries from different sectors like consumer electronics and automobile are expected to drive the growth of the market in the coming years. Moreover, rising disposable income, growing pollution levels and surging demand for quality & uninterrupted power will ensure robust growth of the market.  Additionally, increasing demand for portable and stationary energy storage, escalating number of solar & wind energy projects and surge in electric vehicle demand are among the other major factors expected to aid India lithium-ion battery market over the next five years.

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