lithium ion battery.pptxhhhhhhhhhhhhhhhh

https://chatgpt.com/share/68b43809-9f70-800b-ad68-a2c78c308c94jjjjjjjjjjjjjjjjjjjj

1. 1 Battery

2. 2 Introduction An electrochemical cell involves the conversion of chemical energy into electrical energy (or vice versa) through redox (reduction-oxidation) reactions. An electrochemical cell consists of two half-cells, each containing an electrode (usually a metal) immersed in an electrolyte solution. The key components and principles of an electrochemical cell are: Electrodes Electrolytes Salt Bridge

3. 3 Electrodes Anode: The electrode where oxidation occurs (loss of electrons). Electrons flow away from the anode in the circuit. Cathode: The electrode where reduction occurs (gain of electrons). Electrons flow towards the cathode in the circuit. Electrolytes The solutions in which the electrodes are immersed contain ions that can conduct electricity. The electrolytes help in the movement of ions between the two half-cells, completing the circuit internally. Salt Bridge In many electrochemical cells (like galvanic cells), a salt bridge is used to maintain electrical neutrality by allowing the flow of ions between the two electrolyte solutions, preventing charge buildup.

4. 4 Redox Reactions: At the anode, the oxidation half-reaction occurs where a substance loses electrons. At the cathode, the reduction half-reaction occurs where a substance gains electrons. These reactions are complementary and drive the flow of electrons through the external circuit, generating an electric current. Electrons flow from the anode to the cathode through an external circuit, producing electrical energy that can be harnessed to do work

5. Introduction to batteries Lithium Battery: Construction W orking Applications 5 Types of Cell Types of Electrochemical Cells: Galvanic (Voltaic) Cell: Converts chemical energy into electrical energy spontaneously. For example, a battery. Electrolytic Cell: Uses electrical energy to drive non-spontaneous chemical reactions.

6. The word Battery comes from the old French word “ baterie ” The battery consist of two electrodes that are isolated by a separator and soaked in electrolyte to promote the movements of ions. It is a feeble vessel that is slow to fill and holds limited energy. Battery is an electrochemical cell or often several electrochemical cells connected in series that can be used as a source of direct electric current at constant voltages. Battery is a device which stores chemical energy and converts it into electrical energy through electrochemical reactions and connected together electrically in series. Batteries are commercial electrochemical cells. 6

7. Types of Batteries Primary batteries:- (Disposable/Non-rechargeable) Irreversibly transform chemical energy to electrical energy. They can produce current immediately on assembly. These are most commonly used in portable device that have low current drain. 7 Alkaline Battery : Commonly used in household devices, the electrodes are zinc and manganese-oxide, with an alkaline electrolyte. Zinc-Carbon Battery : Inexpensive and used in low-drain devices. The electrodes are zinc and carbon, with an acidic paste between them that serves as the electrolyte. Lithium Battery : Used in small electronics like watches and calculators due to long life and stability.

8. 2) Secondary Battery:- (R echargeable) Rechargeable and can have their chemical reactions reversed by supplying electrical energy to the cell. 8 Nickel-Metal Hydride (NiMH) Battery : Used in hybrid vehicles and other consumer electronics; it offers better environmental safety than Ni-Cd. Lead-Acid Battery : Common in automobiles for starting engines; known for high power output and reliability. Lithium-Ion (Li-ion) Battery : Widely used in mobile phones, laptops, and electric vehicles (EVs) due to high energy density and long cycle life. Nickel-Cadmium (Ni-Cd) Battery : Used in industrial applications and some cordless tools; it is known for durability but has environmental concerns due to toxic cadmium.

9. 3) Flow Batteries A special type of rechargeable battery where energy is stored in liquid electrolytes that flow through one or more electrochemical cells from one or more tanks. These are scalable and often used for large energy storage applications like grid energy storage. Advantages: Long lasting, Low cost, Low flammability Examples Vanadium Redox Flow Battery (VRFB) : Suitable for large-scale energy storage, such as solar or wind farms. 4) Solid-State Batteries These are advanced batteries where both the electrolyte and electrodes are solid rather than liquid or gel-based. Solid-state batteries promise higher energy density and improved safety compared to traditional batteries. They are still largely in development. 9

10. Differences between Primary, Secondary and Fuel cells: Primary Cell Secondary Cell Fuel Cell It acts as a simple galvanic cell. It acts as a galvanic cell while discharging and electrolytic cell while charging. It acts as a simple galvanic cell. Cell reaction is not reversible. Cell reaction can be reversed. Cell reaction is not reversible Cannot be recharged. Can be recharged Do not store energy Can be used as long as the materials are active in their composition. E.g : Leclanche or dry cell. Zn/NH 4 Cl (20%), ZnCl 2 /MnO 2 /C. emf =1.5V. Can be used again and again by recharging the cell E.g : 1. Lead storage cell 2. Nicol or Nickel cadmium battery emf=1.4 Energy can be withdrawn indefinitely as long as outside supply of fuel is maintained E.g : H 2 -O 2 , CH 3 OH-O 2 Applications: Radios, torches, transistors, hearing aids. Applications: Electronic calculators, electronic flash units & cordless electronic shavers etc. Applications: Space vehicles due to their light weight and the biproduct H 2 O produced is a valuable source of fresh water for astronauts. 10

11. Characteristics of Battery Voltage (Nominal Voltage) Definition : The electrical potential difference between the positive and negative terminals of the battery. It is a measure of the battery's ability to drive electric current. Typical Values : Varies based on the battery type (e.g., 1.5V for alkaline batteries, 3.7V for lithium-ion batteries). Capacity (Ah or mAh ) Definition : The amount of charge a battery can store, usually expressed in ampere-hours (Ah) or milliampere-hours ( mAh ) . Significance : The larger the capacity, the longer the battery can power a device before needing a recharge or replacement. Energy Density Definition : The amount of energy stored in a battery relative to its weight (specific energy, in Wh /kg) or volume (energy density, in Wh /L). Significance : Higher energy density means the battery can store more energy in a smaller or lighter package. This is critical for portable devices and electric vehicles. 11

12. Power Density Definition: The amount of power (energy per unit time) that a battery can deliver relative to its weight (W/kg) or volume (W/L). Significance : Batteries with high power density can deliver large amounts of power quickly, useful in applications requiring high bursts of energy, such as electric cars during acceleration. Cycle Life (Charge/Discharge Cycles) Definition : The number of charge and discharge cycles a battery can undergo before its capacity drops below a specified level (usually 80% of its original capacity). Significance : A longer cycle life means the battery can be used more times before it needs to be replaced. It is a key metric for rechargeable batteries like lithium-ion. 12

13. ADVANTAGES OF BATTERIES: (1) Batteries act as a portable source of electrochemical energy. (2) The portability of electronic equipment in the form of handsets has been made possible by batteries. (3) A variety of electronic gadgets have been made more useful and popular with the introduction of rechargeable storage batteries having reliability, better shelf life and tolerance to service. (4) For all commercial applications, batteries are constructed for their service. For example, batteries for automotives and aircrafts, stand by batteries etc. 13

14. The following requirements should be possessed by the batteries. (1) High capacity, which is very small variation of voltage during discharge. (2) High energy efficiency, which is calculated as % of efficiency = energy released on discharge/energy required for charge x100 (3) High cycle life is required which is the number of charging and discharging cycles before failure. (4) Long shelf-life is required. (5) Tolerance to different service conditions such as variation in temperature, vibration shock, etc. (6) Reliability 14

15. Lithium Ion Batteries:- Introduction Pioneering work of the lithium battery began in1912 under G. N. Lewis, but it was not until the early 1970s that the first non-rechargeable lithium batteries became commercially available, but failed because of instabilities in the metallic lithium used as anode. Lithium is the lightest of all metals, has the greatest electrochemical potential and provides the largest specific energy per weight. 15

16. Lithium Ion Battery The batteries in which lithium ions are used instead of Lithium metal and movement of lithium ion through electrolyte takes place from one electrode to another electrode, such batteries are called as Lithium ion batteries. 16

17. Construction: Anode (Negative Electrode): It is made up of carbon material with a high energy density and large doping capacity of lithium ion. Cathode (Positive Electrode):- It is made up of Metal oxide containing lithium i.e. lithium cobalt oxide (LiCoO 2 ) Lithium iron phosphate ( LiFePO ₄), or lithium nickel manganese cobalt oxide ( LiNiMnCoO ₂). Electrolyte : A liquid or gel like substance that facilitates the movement of lithium ions between the anode and cathode. It is made up of Lithium salts in an organic solvent (LiPF 6 ,LiBF 4 or LiClO 4 in an organic solvent such as ether, ethylene carbonate, dimethyl carbonate and diethyl carbonate) Separator : Porous polymer film placed between the anode and cathode. Prevents the electrodes from coming into direct contact while allowing lithium ions to pass through. Current Collectors : Made from copper (at the anode) and aluminum (at the cathode), these collect and transfer electrons to the external circuit. Voltage: 3.7V 17

18. Working: (Discharging ) At Anode LixC 6 ​→ 6C ​+ xLi + + xe − At Cathode xLi + + xe − + CoO 2 ​ → LiCoO 2 ​ Net Reaction LixC 6 + CoO 2 ​→ LiCoO 2 During discharging, lithium ions move from the anode to the cathode. Electrons flow through the external circuit from the anode to the cathode, producing an electric current that can be used to power electronic devices. Current flows in opposite direction. The movement of ions and electrons from the anode to the cathode allows energy to be released, powering the connected device. 18

19. (Charging) 19 During charging, an external power source applies a voltage to the battery, forcing lithium ions to move from the cathode to the anode through the electrolyte. As lithium ions move to the anode, electrons are transferred from the external circuit to the anode via the current collector. Lithium ions are stored in the anode, and the battery is considered charged. At Cathode LiCoO 2 ​→ Li + + e − + CoO 2 At Anode 6C ​+ Li + + e − ​→ LiC 6 Cell Reaction LiCoO 2 + 6C ​→ CoO 2 + LiC 6

20. Advantages of Li-ion Battery 1 ) High energy density and light weight 2) Long cycle 3) Low internal resistance 4) Simple charge algorithm 5) Low self-discharge 6) Fast charging 20 Disadvantages of Li-ion Battery 1) They are expensive 2) They are not available in standard cell types 3) Safety concerns 4) Environmental Impact 5) Temperature sensitivity

21. Applications 21 The Li-ion batteries are used in cameras, calculators, smart phones and most of the consumer electronics device. They are used in cardiac pacemakers and other implantable device. Electric vehicles: Because of their light weight Li-ion batteries are used for propelling a wide range of electric vehicles such as aircraft, electric cars, advanced electric wheelchairs, radio-controlled models, model aircraft. Power tools: Li-ion batteries are used in tools such as cordless drills, sanders, saws and a variety of garden equipment including whipper-snippers and hedge trimmers

22. Thank You 22