Chemistry of Batteries

Cat: ENE
Pub: 2019
#: 1902b

Theodore L. Brown, et al. and Wikipedia, etc.

19302u

バッテリーの化学

0. Introduction:
1. Lead-acid battery:
2. Alkaline battery:
3. Lithium-ion battery:
4. Fuel battery:
5. Batterty for EV:

0. 序:
1. 鉛蓄電池:
2. アルカリ電池:
3. リチウムイオン電池:
4. 燃料電池:
5. EV用電池:

Title

Remarks

>Top 0. Introduction:

• What is battery?:
  • The positive terminal is cathode, and negative is anode.
  • The negative terminal is source of electrons that will flow through electric circuit to the positive terminal.
  • Battery specifically referred to a device composed of multiple cells.
  • Primary batteries are used once and discarded; the electrode materials are irreversibly changed during discharge. (like alkaline battery)
  • Secondary (=rechargeable) batteries can be recharged multiple times; the electrodes can be restored by reverse current. (like lead-acid battery, and lithium-ion battery)
    • worldwide battery industry generates $48B in sales each ear, with 6% annual growth.
  • Batteries have much lower specific energy (energy per unit mass) than common fuels as gasoline.
    • In automobiles, this is offset by higher efficiency of electric motor in converting chemical energy to mechanical work, compared to combustion engines.
• The first electrical battery;
  was invented by Italian physicist Alessandro Volta in 1799, enabling electrical decomposition (electrolysis) of water into oxygen and hydrogen.
  • In 1800, Volta stacked several pairs of alternating copper and zinc discs (electrodes); an electric current flowed through the voltaic pile and the connecting wire.
  • In 1749, Benjamin Franklin first used the term battery to describe a set of linked capacitors.
• >Top Dynamo:
  19C electrical industry was powered by batteries until the advent of dynamo (electrical generator) in 1870s.
  • Successive improvements in battery facilitated major electrical advanced including rise of telegraph and telephone, then portable computer, mobile phone, and EV.
  • Well cells contain liquid electrolyte and metallic electrodes.; early EV used semi-sealed well cells.
  • the development of Pb-acid battery and subsequent secondary or rechargeable types allowed energy to be restored to the cell.
  • the introduction of Ni and Li based batteries in latter 20C made the development of innumerable portable devices.

0. 序:

>Top 1. Lead-acid Battery:

• Common 1.5V battery: used to power flashlights and consumer electronic devices.
• Greater voltage can be achieved by using multiple voltaic cells, like 12V automotive batteries.
  • Usually anode and cathode compartments are separated by porous barrier.
    • Oxidation occurs at the anode, while reduction at cathode.
    • Electrons flow spontaneously from negative anode to positive cathode.
    • Anions move toward the anode, while cations toward the cathode.
• Pb-acid Battery:
  • commonly used in EV, over 100M produced annually.
  • 12V automotive battery consists of six voltaic cells in series, each 2V.:
    • Cathode $PbO_2$; Anode $Pb$; both are immersed in sulfuric acid.
    • Cathode: $PbO_2+H_2SO_4+3H^{+}+2e^{-} \rightarrow PbSO_4+2H_2O$
    • Anode: $Pb +HSO_4 \rightarrow PbSO_4 +H^{+} +2e^{-}$
    • Standard cell potential can be obtained from the standard reduction potentials:
      • Cathode - Anode= +1.685V -(-0.356V) = +2.041V
    • Solid are excluded from the reaction quotient Q; $Pb(s), PbO_2(s), PbSO_4(s)$ have no effect on the elf of the Pb storage battery.
    • Pb-acid battery can be recharged by external energy to reverse the direction of the equation:
      • $2PbSO_4+2H_2O \rightarrow PbO_2+Pb+2HSO_4^{-}+2H^{+}$

1. 鉛蓄電池:

• >Top Voltaic Cell:
  
• 

>Top 2. Alkaline Battery:

• The most common primary (non-rechargeable) battery is alkaline battery.; $10^{10}$ alkaline batteries are produced annually.
  • Anode of this battery consists of powdered $Zn$ metal immobilized in a gel in contact with a concentrated solution of $KOH$. (hence alkaline battery)
  • Cathode is a mixture of $MnO_2(s)$ and graphite, separated by porous fabric separator.
  • The battery is sealed in a steel can to reduce leakage of KOH.
  • The cell reactions can be approximately represented as follows:
    • Cathode: $2MnO_2+2H_2O+2e^{-}\rightarrow 2MnO(OH)+2OH^{-}$
    • Anode: $Zn+2OH \rightarrow Zn(OH)_2 +2e^{-}$
  • The emf of an alkaline battery is 1.55V at room temperature; provides superior performance over the older dry cells that are also based on $MnO_2$ and $Zn$

2. アルカリ電池:

• Alkaline Battery
• 

>Top 3. Lithium-ion (LIB) Battery:

• The tremendous growth in high-power portable electronic devices (cellular phone, note PC, and video recorder) has increased the demand for lightweight.
  • features: high density, no memory effect, low self-discharge, and safety risks when damaged.
• $Li^{+}$ move from the negative electrode to the positive electrode during discharge.
  • $Li^{+}$ battery uses an intercalated Li compound as one electrode material, compared to the metallic Li used in a non-rechargeable Li battery.
  • mostly based on $LiCoO_2$
  • $LiFePO_4; LiMn_2O_4$, and $Li_2MnO_3 (LMO)$, and $LiNiMnCoO_2 (LMC)$ are lower energy density but longer lives and less likelihood of fire or explosion.
  • $LiNiCoAlO_2$ (NCA) and $Li_4Ti_5O_{12}$ (LTO) for particular niche roles.
• >Top Until recently, the most common rechargeable battery was Ni-Cd (nicad) battery.
  • The electrode reactions are the following:
    • Cathode: $2NiO(OH)+2H_2O+2e^{-} \rightarrow 2Ni(OH)_2+2OH^{-}$
    • Anode: $Cd+2OH^{-} \rightarrow Cd(OH)_2+2e^{-}$
  • A single nicad voltaic cell has an emf of 1.30V; typically contain more cells in series to produce higher emfs.
  • But Cd is a toxic heavy metal; rough 1.5B nicad batteries are produced annually.
• Development of $NiMH$ battery:
  • Anode consists of a metal alloy, such as $ZrNi_2$, that has the ability to absorb $H_2$ atoms.
  • During oxidization at the anode, $H_2$ atoms are released as $H_2O$
• >Top The newest rechargeable battery to receive large use in consumer electronic (and EV), Li-ion batteries achieve a greater energy density.
  • Li-ion battery achieves a greater energy density than Ni-based battery.
  • Li-ion can be inserted into layers of graphite.
  • During discharge Li-ions migrate between two different layered materials that serve as the anode and cathode of the cell.
• History of development of LIB:
• 1973: Adam Heller proposed lithium thionyl chloride battery.
• 1977: Samar Basu demonstrted electrochemical intercalation of $Li$ in graphite.
• 1979: Ned A. Godshall, and in 1980 John Goodenough and Koichi Mizushima both demonstrated a rechargeable lithium cell in 4V using $LiCoO_2$ as the positive electrode and $Li$ metal as the negative electrode.
• 1980: Richard Yazami demonstrated the reversible electrochemical intercalation of $Li$ in graphite.
• 1982: Godshall et al. were awarded US Patent on the use of $LiCoO_2$
• 1983: Michael Thackeray, John Goodenough et al. further developed manganese spinel as a positive electrode.
• 1985: Akira Yoshino assembled prototype cell using carbonaceous material into which $Li^{+}$ could be inserted as one electrode, and $LiCoO_2$ as the other. By using materials without metallic $Li$, safety was dramatically improved. $LiCoO_2$ enabled industrial-scale production.
• Commercial production:
• 1991: Sony and Asahi Kasei released first commercial LIB.
• 2011: LIB accounted 66% of all portable secondary battery sales in Japan.
• 2012: John Goodenough, Rachid Yazami and Akira Yoshino received 2013 IEEE medal for environmental and safety technologies of LIB.
• 2014: Then National Academy of Engineering recognized John Goodenough, Yoshio Nishi, Rachid Yamami and Akira Yoshino for their pioneering efforts in the field.
• 2016: Global LIB production capacity was 28GWh, with 16.4 GWh in China.
• >Top Tesla's Gigafactory ($5B):
  • Panasonic reached agreement with Tesla to invest $1.6B in a factory, leading battery cell production of manufacturing.
  • Production Group of LIB:
  1. Tesla/Panasonic Group
  2. Nissan/AESC (Nissan+NEC) Group
  3. GM/VW/LG Chem Group
  4. Mitsubishi/GS Yuasa/Toshiba Group
  • Gigafactory-1: Reno, Nevada, US;
  • Tesla held a grand opening on 2016/7/29, having only 3/21 blocs completion of the Gigafactory; which began mass production in 2017/1; expected to be completed by 2020.
  • the factory is aligned on true north, is designed to be energy self-reliant (solar, wind, and geothermal), largest footprint in the world.
  • Model-3 production ramped up to about 5,000
  • Gigafactory-2: Buffalo, New York
  • Gigafactory-3: Shanghai, China; began construction
  • Gigafactory-4?: in Europe, plans underway
• EV Battery production <Fig.>:
• CATL (Comtemporary Amperex Technology, 宁德时代新能源科技): having plan to produce 88GWh by around 2020.
• BYD Company Ltd. (比亚迪股份): will produce 60GWh in 青海省 by 2020; particulary higher energy density battery of NMC811 (Ni8-Mn1-Co1 cathode) than MNC622 (Ni6-Mn2-Co2)
  • it is importnat to decrease use of rare metal Co from 2 to 1.
  • Co is said as 'the Wall of EV Proliferation', which is mostly mined unstable DRC (Democratic Republic of Congo)
  • Tesla aims to reduce Co in producing NCA (Ni-Co-Al) battery using only 3% of Co.

3. リチウムイオン電池:

• Li-ion Battery (LIB) structure:
• 
  • Positive electrode: $LiCoO_2; LiMn_2O_4; LiFePO_4$
  • Negative electrode: $C; Si; SnO_2$
  • Electrolyte: $LiPF_6; LiClO_4$
    
    
• AA Size (L) and 18650 for Tesla Model-S; Tesla says that now new 21700 type battery with 70mm-L, 21mm-D & 24.245mm3, which is bigger (46%), improved energy efficiency about 15%, energy density 877.5Wh/L and cell capacity 21.275Wh than 18650 type battery.
• 
  
  
• Tesla's Gigafactory-1:
• 
• EV Battery Production Share:
• 

>Top <Next Generation Cathode - NMC 811>

• Various Li-ion Batteries:

• $LiCoO_2$	LCO	MobilePhone, Laptop PC, Camera
  $LiMn_2O_4$	LMO	Elec tool, Medical, Hobby
  $LiFePO_4$	LFP	Elec tool, Medical, Hobby
  $LiNiMnCoO_2$	NMC	Elec tool, Medical, Hobby
  $LiNiCoAlO_2$	NCA	EV, Gridstorage
  $Li_4Ti_5O_{12}$	LTO	EV, Gridstorage

• NMC (Ni-Mn-Co) Cathode:
  • This is the next-generation cathode - better and chearper, pushing EVs beyond 500km driving range and soon to price parity with ICE (Internal Combustion Engine).
  • LIB compostion <Fig.>:
    NMC811 is a cathode compostion with 80% Ni 10% Mn, and 10% Co. NMC cthodes with different Ni-Mn-Co compositions have been around for almost 20 years. Following the initial commercil success of NMC111 (as NMC333, NMC cathodes have become mainstream, being used in BMW-i3, Chevy Bolt, or new Nissan Leaf.
    • Industry has been improving NMC technology by steadily increasinng Ni content (e.g. NMC433, NMC532, or most recent NMC622)
    • The cells have higher capacity and lower weight; the battery packs store more energy and better driving range.
    • It is NCA (Ni80-Co15-Al), but are doped with Al as opposed to Mn.
  • >Top Ni is largely responsible for cathode capacity, with Mn and Co helping chemical and structure stability.
    • 20% increase of Ni content (from NMC622 to NMC 811) pushes the capacity of NMC811 to around 200 mAh/g (discharge potential 3.8V) <Fig.>.
    • Co Price (LME):
      Co is very expensive with very questionable supply chain (like Kawama mine, Congo). Note, cathode materials account for about 1/4 of the cell cost. While Ni and Mn prices are relatively low and steady, the cost of Co skyrockted by more than 200% (from $35K to $75K/ton in 2017 alone)
    • NMC811 is more sensitive chemistry; requiring improved synthetic processes than NMC333 or even NMC622.
      • NMC is synthesized with Ni in oxidised state $Ni^{3+}$, largely due to instabliity of $Ni^{3+}$ ion at high synthetic temperatures.
      • NMC comes alog with undersirable residues mainly Li-based that need to be removed or pssivated.
      • NMC is also sensitive to moisture and air.
      • Fully oxidised $Ni^{4+}$ is reactive and so its exessive amount increase unwanted side reaction with the electrolyte.
      • Capcity and cycle life don't necessarily go together for NMC811.
      • Ni-rich NMC cathodes are sensitive to elevated temperature - release more $O_2$ than their counter parts; also undergo more structural changes. <Fig.>
      • LG CHem and SK Innovation claim NMC811 will be in mass production by the end of 2019, but safety of NMC811suggest the timescals might be more conservative.
    • NCA development:
      • Note, NCA technology (by Panasonic and Tesla) is developing as well. It's very similar to NMC811, whether you consider its Ni-rich chemistry, superior capacity, more complicated manufacturing, or stability issues.
• Tesla supplied ESS (Energy Storage System) in South Australia.
  • World's largest ESS with capacity 100/129MWh, which was constructed within 100 days.
  • This ESS Farm having 315MW capacity is used as the backup of Neoen's Hornsdale Wind Farm near Jamestown to stabilize the grid in the summer..
  • Tesla decided to use Samsung SDI cells to make it on time.
  • The cost is estimated at some $50M.

• LIB Compostion: (Li/Ni/Co/Mn/Al)
• 
• LIB Capacity:
• 
• LIB Temperature Sensitivity:
• 
• LIB Structurel Changes:
  
• 

>Top 4. Fuel Cell:

• Many substances are used as fuels.
• Thermal energy released by combustion is often converted to electrical energy (maximum only 40%).
• Direct production of electricity from fuels by a voltaic cell could yield a high rate of conversion.
  • Fuel cell is not battery because it is not self-contained system.
  • Fuel cells is an electrochemical cell that converts the potential energy form a fuel in electricity through electrochemical reaction of $H_2$ with $O_2$ or other oxidizing agent; which requires continuous source of fuel and $O_2$ (usually from air) to sustain the chemical reaction, while in a battery the chemical energy comes from chemical present in the battery.
  • The first fuel cells were invented in 1838.
  • The first commercial use came in NASA a century later to generate power for satellites and space capsules.
• The most promising fuel-cell system involves the reaction of $H_2$ and $O_2$ to form $H_2O$
• Cathode: $4e^{-}+O_2+2H_2O \rightarrow 4OH^{-}$
• Anode: $2H_2+4OH^{-} \rightarrow 4H_2O+4e^{-}$
• The standard emf of an $H_2-O_2$ fuel cell is +1.23V
• Until recently, fuel cells were impractical because of high operating temperatures to allow the cell reaction to occur at an appreciable rate.
  • Semipermeable membranes and catalysts allow for operation of $H_2-O_2$ fuel cells below 100ºC
  • fuel cell-based engines are more efficient than gasoline engines with respect to the amount of chemical energy that is converted to work.

4. 燃料電池:

• $H_2-O_2$ fuel cell:
• 

>Top 5. Battery for EV:

• The battery makes up a substantia cost of BEVs, which unlike for fossil-fueled cars.
  • Since the late 1990s, advances in battery technology have been driven for portable electronics (laptop computers and mobile phones.)
  • The cost of EV batteries was reduced by more than 35% from 2008 to 2014.
  • Most EV used new variations on Li-ion chemistry that sacrifice specific energy and specific power to provide fire resistance, environmental friendliness, very rapid charges, and very long lifespans.
• EV Battery cost:
• In 2010; $10k for 25kWh capacity ($400 per kWh)
  • It was estimated that at most 10 years would pass before the battery price to 1/3.
  • MIT estimate the cost of EV battery packs to be $225-500 per kWh by 2020.
  • US DOE et cost targets of $300 per kWh in 2015 and $125 by 2022.
  • In 2016, the world had a Li-ion production capacity of 41.6 GWh.
• BEVs achieve about 8 km/kWh
• In 2010, Nissan Leaf (24kWh capacity) was reportedly produced at a cost of $18,000 (about $750/kWh).
• In 2012, McKinsey Quarterly estimated that $3.50/gallon equate to $250/kWh; forecasts pack costs to be $190/kWh by 2020 and $100/kWh around 2030.
• In 2015, GM revealed that a cost of $145/kWh by 2016, expecting $100/kWh by 2021.
• Resources for Li-ion Battery:
  • The demand for Li, heavy metals, and other specific elements (Nd=Neodymium, B, and Co) required for battery production.
  • Li Availability:
    • 7g of LCE (Li carbonate equivalent) are used in a smartphone and 30g in a tablet computer.
    • 5kg of LCE are used for Hybrid car, while 80kg for Tesla EV.
    • The largest world reserves of Li and other rare metals are located in limited countries (Congo, Bolivia, China).
    • It is estimated that there are sufficient Li reserves to power 4B EVs.

5. EV用電池:

>Top 6. Rare metals used for EV:

• 1/3 value of EV is battery cost:
• Mines for such rare metals are distributed unevenly worldwide <Fig.>
  • Li, Co, Ni are <Fig.>
    • Li metal:
      • Spodumene, a pyroxene mineral consisting of $LiAl(SiO_3)_2$
      • World production of Li via spodumene is about 80K tons/y, primarily from Greebushes pegmatite of Western Australia (2.4% $Li_2O$), Argentina, China, and Chile.
      • The largest reserve of Li is in dry salt lake 'Salar de Uyuni', 3,700m altitude area in Bolivia (5.4M tons)
  • Graphite, Didymium (mix of rare earth Nd-60 neodymium and Pr-59 praseodymium)

6. EV用希少資源:

Comment

• The essence of EV (or BEV) is to use efficient motor power, loaded with large amount of rechargeable batteries.
• Chemistry of batteries have long history of development, but is still developing even now.
• The value of Li or other rare metals will replace the position of fossil fuel resouces.

• EVの本質は、巨大な二次電池を搭載して、効率的なモーターパワーを利用することにある。
• 電池の化学の発展の歴史は古いが、今でも発展途上にある。
• Liその他の希少金属は、化石燃料資源の地位と交代することになろう。