Lithium ion batteries have a wide range of applications. It has its advantages as well as a host of disadvantages which were experienced by multinational companies across the globe in various industries, a stark example would be the grounding of aircraft, recalling smartphones etc. This article gives brief inputs on Lithium-ion batteries and the latest developments.

1. In the batteries, lithium ions move from the negative electrode through an electrolyte to the positive electrode during discharge, and back when charging. Lithium-ion batteries use an intercalated lithium compound as the material at the positive electrode and typically graphite at the negative electrode. The batteries have a high energy density, no memory effect (other than LFP cells) and low self-discharge.
2. Pioneer work with the lithium battery began in 1912 under G.N. Lewis but it was not until the early 1970s when the first non-rechargeable lithium batteries became commercially available. lithium is the lightest of all metals, has the greatest electrochemical potential and provides the largest energy density for weight.

Lithium batteries were proposed by British chemist and co-recipient of the 2019 Nobel prize for chemistry M. Stanley Whittingham, now at Binghamton University, while working for Exxon in the 1970s.Lithium-Ion Batteries – Latest News from ISRO

1. ISRO’s VSSC has successfully developed and qualified lithium-ion cells of capacities ranging from ‘1.5 Ah to 100 Ah’ for use in satellites and launch vehicles.
2. According to ISRO, with the successful deployment of indigenous lithium ion batteries in various missions, VSSC is planning to transfer this technology to the industries to establish production facilities for producing lithium ion cells to cover the entire spectrum of the country’s power storage needs.
3. The Indian Space Research Organisation(ISRO) had selected ten companies in 2019 for the transfer of its Lithium-ion cell technology.
4. China dominates the Li-ion battery market. Around three-quarters of battery cell manufacturing capacity is in China, and Chinese companies have unparalleled control of required domestic and foreign battery raw materials and processing facilities.
5. India has been importing Li-ion batteries from China, Japan and South Korea.

Lithium-ion Battery – Applications

1. Electronic gadgets
2. Tele-communication
3. Aerospace
4. Industrial applications
5. Lithium-ion battery technology has made it the favourite power source for electric and hybrid electric vehicles.

Lithium-ion Cell technology – Benefits

1. Long life cycle
2. High Voltage
3. High Storage Characteristics
4. High Energy Density

Lithium-ion Battery – Major Issues

1. Lithium-Ion batteries can be a safety hazard since they contain flammable electrolytes, and if damaged or incorrectly charged can lead to explosions and fires.
2. There have been several incidents involving batteries on Boeing 787s.
3. Samsung was forced to recall Galaxy Note 7 handsets following lithium-ion fires
4. Requires protection circuit to maintain voltage and current within safe limits.
5. Expensive to manufacture – about 40 percent higher in cost than nickel-cadmium.
6. Not fully mature – metals and chemicals are changing on a continuing basis.

Block Diagram of Electric Vehicle

Lets Take the design specification of TATA Nexon Electric Vehicle Drivetrain

Electric Drivetrain

Motor Type- Permanent Magnet Synchronous Motor

Mechanical DC Motor Power-900 W

Vehicle Body System

1. The Chassis. The chassis of an automobile incorporates all the major assemblies consisting of an engine, components...
2. The Engine. The engine is the source of motive power to an automobile. Obviously, it is a very important part of the...
3. The Transmission System. The transmission system transmits power developed by the engine to the road wheels. The...
4. The Body. The use of a separate frame to which the body structure is attached is now almost obsolete except for some...
5. The Auxiliaries.
6. Simulink model of Vehicle body subsytem is as under

Explaination of VehicleSub system

The vehicle Subsystem Consist of

1. Tire

2. Vehicle body

3. Simple Gear

Represents the longitudinal behavior of a highway tire characterized by the tire Magic Formula. The block is built from Tire-Road Interaction (Magic Formula) and Simscape Foundation Library Wheel and Axle blocks. Optionally, the effects of tire inertia, stiffness, and damping can be included.

Connection A is the mechanical rotational conserving port for the wheel axle. Connection H is the mechanical translational conserving port for the wheel hub through which the thrust developed by the tire is applied to the vehicle. Connection N is a physical signal input port that applies the normal force acting on the tire. The force is considered positive if it acts downwards. Connection S is a physical signal output port that reports the tire slip. Optionally expose physical signal port M by setting Parameterize by to Physical signal Magic Formula coefficients. Physical signal port M accepts a four element vector corresponding to the B, C, D, and E Magic Formula coefficients.

Vehicle Body

The block accounts for body mass, aerodynamic drag, road incline, and weight distribution between axles due to acceleration and road profile. The vehicle can have the same or a different number of wheels on each axle. Optionally include pitch and suspension dynamics or additional variable mass and inertia. The vehicle does not move vertically relative to the ground.

Connection H is the mechanical translational conserving port associated with the horizontal motion of the vehicle body. The resulting traction motion developed by tires should be connected to this port. Connections V, NF, and NR are physical signal output ports for vehicle velocity and front and rear normal wheel forces, respectively. Wheel forces are considered positive if acting downwards. Connections W and beta are physical signal input ports corresponding to headwind speed and road inclination angle, respectively. If variable mass is modeled, the physical signal input ports CG and M are exposed. CG accepts a two- element vector representing the x and y distance offsets from vehicle CG to additional load mass CG. M represents the additional mass. If both variable mass and pitch dynamics are included, the physical signal port J accepts the inertia of the additional mass about its own CG.

Simple Gear

The complete Drivetrain

State of Charge Subsystem

This Subsystem Consist of

1. Battery

2. Current Controlled Source

3.Rate Transition

4. Gain

5. Discrete Time Integrater

6. Subtract Block

7.Scope

8. Electrical reference

Battery

V = Vnom*SOC/(1-beta*(1-SOC))

where SOC is the state of charge and Vnom is the nominal voltage. Coefficient beta is calculated to satisfy a user-defined data point.