Week 1 Understanding Different Battery Chemistry

1.Prepare a table which includes materials & chemical reactions occurring at the anode and cathode of LCO, LMO, NCA, NMC, LFP and LTO type of lithium ion cells.Give your detailed explanation on it.

 A lithium-ion battery consists of two or more electrically connected electrochemical cells. When the battery is charged, the ions tend to move towards the negative electrode or the anode. When the battery gets completely discharged, the lithium ions return back to the positive electrode, i.e., the cathode.

   Lithium-ion batteries work on the rocking chair principle. Here, the conversion of chemical energy into electrical energy takes place with the help of redox reactions. Typically, a lithium-ion battery consists of two or more electrically connected electrochemical cells. When the battery is charged, the ions tend to move towards the negative electrode or the anode. When the battery gets completely discharged, the lithium ions return back to the positive electrode, i.e., the cathode. This means that during the charging and discharging process, the lithium ions move back and forth between the two electrodes of the battery, which is why the working principle of a lithium-ion battery is called the rocking chair principle.

                                         

i) Lithium cobalt oxide(LCO) battery

                                       

LCO (Lithium cobalt oxide) was invented in the year 1991. Its anode material is LiaC6, the cathode material is LibCoO2 and the carrier is Li+.It is used in various applications ranging from electronic devices to all laptops and phone batteries. The majority of lithium-ion batteries for portable devices are cobalt-based. The system contains a cobalt oxide cathode (positive electrode) and graphite carbon anode (negative electrode).

Fully reduced lithium cobalt oxide can be prepared by heating a stoichiometric mixture of lithium carbonate  Li₂CO₃ and cobalt(II,III) oxide Co₃O₄ or metallic cobalt at 600–800 °C, then annealing the product at 900 °C for many hours, all under an oxygen atmosphere.

Nanometer-size particles more suitable for cathode use can also be obtained by calcination of hydrated cobalt oxalate β-CoC₂O₄·2H₂O, in the form of rod-like crystals about 8 μm long and 0.4 μm wide, with lithium hydroxide LiOH, up to 750–900 °C.

A third method uses lithium acetate,cobalt acetate, and citric acid in equal molar amounts, in water solution. Heating at 80 °C turns the mixture into a viscous transparent gel. The dried gel is then ground and heated gradually to 550 °C.

 ii)Lithium-ion manganese oxide (LMO)battery

                                             

A lithium-ion manganese oxide battery (LMO) is a lithium ion cell that uses manganese dioxide, MnO2, as the cathode material. They function through the same intercalation/de-intercalation mechanism as other commercialized secondary battery technologies, such as LiCoO2. Cathodes based on manganese-oxide components are earth-abundant, inexpensive, non-toxic, and provide better thermal stability.

A lithium ion manganese oxide battery (LMO) is a lithium-ion cell that uses manganese dioxide,MnO2, as the cathode material. They function through the same intercalation/de-intercalation mechanism as other commercialized secondary battery technologies, such asLiCoO2. Cathodes based on manganese-oxide components are earth-abundant, inexpensive, non-toxic, and provide better thermal stability.

iii)Lithium nickel cobalt aluminium oxides (NCA) battery

   The lithium nickel cobalt aluminium oxides (abbreviated as Li-NCA, LNCA, or NCA) are a group of mixed metal oxides. Some of them are important due to their application in lithium ion batteries. NCAs are used as active material on the positive pole (which is the cathod when the battery is discharged). NCAs are composed of the cations of the chemical  elements lithium,nickel,cobaly and aluminium. The most important representatives as of this date have the general formula LiNi_xCo_yAl_zO₂ with x + y + z = 1. In case of the NCA comprising batteries currently available on the market, which are also used in electric cars and electric application, x ≈ 0,8, and the voltage of those batteries is between 3.6 V and 4.0 V, at a nominal voltage of 3.6 V or 3.7 V. A version of the oxides currently in use in 2019 is LiNi_0,84Co_0,12Al_0,04O₂.

iv)Lithium Nickel Manganese Cobalt Oxide (NMC) battery

 What is an NMC battery? In short, NMC batteries offer a combination of Nickel, Manganese and Cobalt. They are sometimes known as Lithium Manganese Cobalt Oxide batteries. NMC batteries have a high specific energy or power.

Lithium nickel manganese cobalt oxides (abbreviated Li-NMC, LNMC, or NMC) are mixed metal oxides oflithium,nickel,manganes and cobalt. They have the general formula LiNi_xMn_yCo_zO₂. The most important representatives have a composition with x + y + z that is near 1, with a small amount of lithium on the transition metal site. In commercial NMC samples, the composition typically has < 5% excess lithium.Structurally materials in this group are closely related tolithium cobalt(III) oxide  (LiCoO₂) and have a layered structure but possess an ideal charge distribution of Mn(IV), Co(III), and Ni(II) at the 1:1:1 stoichiometry. For more nickel-rich compositions, the nickel is in a more oxidized state for charge balance. NMCs are among the most important storage materials for lithium ions in lithium ion batteries. They are used on the positive side, which acts as the cathode  during discharge.

 v)Lithium iron phosphate battery(LFP) batteries

  LFP batteries stands for Lithium iron phosphate(LiFePO4) batteries, which is known as li-phosphate batteries as well. They use phosphate as cathode material. In addition, they benefit from the low resistance properties that enhance their thermal stability and safety.  

The lithium iron phosphate battery (abbreviated as Li-IP, LFP (lithium ferro-phosphate) or LiFePO₄ battery) is a type oflithiun-ion battery usinglithium iron phosphate  (LiFePO₄) as the cathode material, and agraphitic carbon electrode  with a metallic backing as the anode. The energy density of an LFP battery is lower than that of other common lithium ion battery types such as nickel manganes cobalt(NMC) and nickel cobalt aluminum(NCA), and also has a lower operating voltage,CATL's  LFP batteries are currently at 125 watt hours (Wh) per kg, up to possibly 160 Wh/kg with improved packing technology, while BYD's  LFP batteries are at 150 Wh/kg, compared to over 300 Wh/kg for the highest NMC  batteries. Notably, the energy density of Panasonic’s “2170” NCA batteries used in 2020 in Tesla’s Model 3 is around 260 Wh/kg, which is 70% of its "pure chemicals" value.

Because of their lower cost, high safety, low toxicity, long cycle life and other factors, LFP batteries are finding a number of roles in vehicle use, utility-scale stationary applications, and backup power. LFP batteries are cobalt-free. As of Q1 2021, LFP type battery market share reached 24.1%, with chinese manufacturer holding a near monopoly, and is expected to rise further to surpass NMC  type batteries.

 vi)Lithium-titanate-oxide(LTO) battery

                                           

The lithium-titanate-oxide (LTO) battery is a type of rechargeable battery which has the advantage of being faster to charge than other lithium-ion batteries, but the disadvantage of having a much lower energy density.

A lithium-titanate battery is a modified lithium-ion battery that uses lithium-titanate nanocrystals, instead of carbon, on the surface of its anode. This gives the anode a surface area of about 100 square meters per gram, compared with 3 square meters per gram for carbon, allowing electrons to enter and leave the anode quickly. Also, the redox potential of Li+ intercalation into titanium oxides is more positive than that of Li+ intercalation into graphite. This leads to fast charging (higher charging current) being much safer in the case of the titanate, than in the case of carbon, since lithium dendrites are less likely to form in the former case. Lithium-titanate cells last for 3000 to 7000 charge cycles; a life cycle of ~1000 cycles before reaching 80% capacity is possible when charged and discharged at 55 °C (131 °F), rather than the standard 25 °C (77 °F).

A disadvantage of lithium-titanate batteries is their lower inherent voltage (2.4 V), which leads to a lowerspecific energy. (about 30–110 Wh/kg) than conventional lithium-ion battery technologies, which have an inherent voltage of 3.7 V. Some lithium-titanate batteries, however, have an energy density. of up to 177 Wh/L.

2.Compare the differences between each type of Li+ion batteries based on their characteristics

There are different types of lithium-ion batteries and the main difference between them lies in their cathode materials. Different kinds of lithium-ion batteries offer different features, with trade-offs between specific power, specific energy, safety, lifespan, cost, and performance