2019 Nobel Prize in Chemistry
Reason for Award
for the development of lithium-ion batteries
Laureates
United States of America
United Kingdom of Great Britain and Northern Ireland, United States of America
Japan
Explanation
The phones and game machines we use every day contain small batteries. These are called “lithium-ion batteries,” and they can be charged over and over again. The three scientists who won the 2019 Nobel Prize in Chemistry perfected the way these batteries work. Inside the battery, tiny lithium particles move back and forth between a plus side and a minus side. When we charge the battery, lithium gathers on the minus side; when we use it, the lithium goes back to the plus side. This movement creates electricity that powers our devices. Because the battery is light and powerful, it is also used in electric cars and large boxes that store energy for houses.
Related Keywords
lithium-ion battery
A lithium-ion battery is a rechargeable cell in which lithium ions shuttle reversibly between a cathode and an anode. First commercialized by Sony in 1991, it now powers everything from smartphones to electric cars. Compared with other chemistries, it offers superior gravimetric and volumetric energy density and is free from the memory effect. Continuous advances in electrode compositions and electrolyte formulations have improved fast-charging capability, cycle life, and safety. Research is currently exploring all-solid-state designs and the re-introduction of lithium-metal anodes to push performance even further.
intercalation
Intercalation is the reversible insertion of small ions or molecules into the gaps of layered or channel-type solids without major disruption of the host lattice. In Li-ion batteries, Li⁺ is intercalated and de-intercalated within layered oxides or graphite to store energy. The associated volume change is moderate, giving excellent structural stability over many cycles. Electrode design therefore focuses on maintaining continuous ion-diffusion pathways while ensuring sufficient electronic conductivity of the host. The same concept is being extended to Na-ion, Mg-ion, and other multivalent systems.
cathode
The cathode is the electrode that undergoes reduction during discharge and largely defines the cell voltage and capacity. Practical chemistries include LiCoO₂, Li(Ni, Mn, Co)O₂, and LiFePO₄, each with distinct voltage, cost, and thermal-stability profiles. Higher cell voltages are obtained by exploiting high oxidation states of transition metals, although this increases lattice-oxygen instability and oxygen evolution risks. Surface coatings and elemental doping are widely investigated to suppress side reactions with the electrolyte and extend service life. Candidate next-generation cathodes include high-nickel layered oxides and lithium-rich spinels, aiming for cell energies around 300 Wh kg⁻¹.
anode
The anode is oxidized during discharge; in most Li-ion cells it is graphite. Graphite intercalates lithium up to LiC₆, giving a theoretical capacity of 372 mAh g⁻¹ and long cycle life due to stable SEI formation. To increase capacity, silicon, tin alloys, and lithium metal are being explored, but they face challenges of volumetric expansion and safety. Improvements in anode performance directly raise the cell’s energy density, requiring coordinated advances in materials, binders, and interface control. Suppressing lithium dendrite formation at the anode is also critical for fast-charging technologies.
lithium cobalt oxide
LiCoO₂, reported by Goodenough in 1980, is a layered rocksalt-type cathode featuring high operating voltage and good electronic conductivity. It was widely adopted in early small-format cells, driving the spread of lithium-ion technology. Concerns include the limited availability and high cost of cobalt and oxygen release leading to thermal runaway. Consequently, Ni- and Mn-substituted NCM materials and Fe-based phosphates have been developed as lower-cobalt alternatives. Stabilization of LiCoO₂ at high 4.2 V operation uses Al/Mg doping and surface coatings, techniques now deployed commercially.
graphite
Graphite consists of stacked sp² carbon layers that can intercalate lithium, making it the most widespread anode material. It offers high reversible capacity at low bulk density and requires only small amounts of conductive additives, advantageous for high-energy cells. During initial charging, electrolyte solvents are reduced, forming a few-nanometer SEI film that protects the electrode surface. Lithium plating at low temperatures or under fast-charge conditions and subsequent dendrite growth pose safety challenges. Alternatives such as hard/soft carbons, tailored particle morphologies, and electrolyte additives are being developed to mitigate these issues.
energy density
Energy density expresses the amount of energy stored per unit mass or volume and directly affects battery size and weight. Li-ion cells achieve practical values of 150–250 Wh kg⁻¹, far surpassing lead-acid and Ni-Cd systems. Increasing specific capacity of materials and minimizing dead volume in packaging are the main pathways to higher density. Rising energy density elevates thermal-runaway risk, necessitating robust thermal management and flame-retardant electrolytes. Research targeting ≥400 Wh kg⁻¹ for aircraft and long-range EVs focuses on solid-state or lithium-sulfur chemistries.
electrolyte
The electrolyte serves as an ionic conductor, transporting Li⁺ between electrodes while electrically insulating them. Current liquid systems dissolve LiPF₆ in organic solvents such as ethylene carbonate (EC) and dimethyl carbonate (DMC). Decomposition at elevated temperatures and HF generation leading to metal dissolution limit cell lifetime. Stability is enhanced through fluorinated additives, highly concentrated electrolytes, and flame-retardant phosphate solvents. Solid-state batteries investigate sulfide, oxide, and polymer electrolytes to eliminate leakage and flammability issues.
solid electrolyte interphase
The SEI is a nanoscale composite film formed by reductive decomposition of the electrolyte on the anode surface; it blocks electrons while allowing Li⁺ transport. It prevents further solvent breakdown and thus governs cell reversibility and lifetime. SEI composition varies with solvent, salt, additives, and temperature, typically containing LiF, Li₂CO₃, and polymeric species. Non-uniform SEI increases resistance and promotes dendrite growth, so techniques to form uniform, elastic films are actively studied. In-situ and operando characterization now enables real-time observation of SEI formation and regeneration processes.
electric vehicle
An electric vehicle (EV) propels itself with an electric motor powered by energy stored in onboard lithium-ion batteries, burning no fossil fuel directly. Low noise and zero tailpipe emissions make EVs attractive for reducing air pollution and greenhouse gases. Battery cost and driving range govern adoption, spurring work to raise Wh kg⁻¹ and Wh L⁻¹ while maintaining cycle life and safety. Deployment of fast-charging infrastructure, integration with renewables, and battery recycling are key to a sustainable EV ecosystem. Second-life use of vehicle batteries and vehicle-to-grid (V2G) services are emerging components of a new energy landscape.