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The 2019 Nobel Prize in Chemistry has been awarded to John B. Goodenough, M. Stanley Whittingham and Akira Yoshino for their contributions in the development of lithium-ion batteries, a technology that has revolutionized our way of life. Here we look back at the milestone discoveries that have shaped the modern lithium-ion batteries for inspirational insights to guide future breakthroughs. The rechargeable lithium-ion batteries have transformed portable electronics and are the technology of choice for electric vehicles. They also have a key role to play in enabling deeper penetration of intermittent renewable energy sources in power systems for a more sustainable future. A modern lithium-ion battery consists of two electrodes, typically lithium cobalt oxide (LiCoO 2) cathode and graphite (C 6) anode, separated by a porous separator immersed in a nonaqueous liquid electrolyte using LiPF 6 in a mixture of ethylene carbonate (EC) and at least one linear carbonate selected from dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC) and many additives. During charging, Li-ions move from the LiCoO 2 lattice structure to the anode side to form lithiated graphite (LiC 6). During discharging, these ions move back to the CoO 2 host framework, while electrons are released to the external circuit. It is this shuttling process or what is called rocking-chair chemistry that has revolutionized our modern life. Materials discoveries Anode. Lithium metal is the lightest metal and possesses a high specific capacity (3.86 Ah g −1) and an extremely low electrode potential (−3.04 V vs. standard hydrogen electrode), rendering it an ideal anode material for high-voltage and high-energy batteries. However, the electrochemical potential of Li + /Li lies above the lowest unoccupied molecular orbital (LUMO) of practically known non-aqueous electrolytes, leading to continuous electrolyte reduction unless a passivating solid electrolyte interface (SEI) is formed 1. The SEI is susceptible to damage and repairs nonuniformly on the surface of lithium metal owing to the large volume change and high reactivity of lithium metal, leading to dendrite growth, which could cause cell to short-circuit and catch fire (Fig. 1a). To avoid safety issues of lithium metal, Armand suggested to construct Li-ion batteries using two different intercalation hosts 2,3. The first Li-ion intercalation based graphite electrode was reported by Besenhard showing that graphite can intercalate several alkali-metal ions including Li-ions 4. Graphite intercalates Li-ions based on a layered structure with half-filled p z orbitals perpendicular to the planes that can interact with the Li 2s orbitals to limit volume expansion and dendrite growth. However, the specific capacity of graphite (LiC 6 , 0.372 Ah g-1) 1 is much smaller than that of lithium metal. It was until a total recall of lithium metal batteries by Moli

Foodborne pathogens like Listeria monocytogenes can cause various illnesses and pose a serious threat to public health. They produce species-specific microbial volatile organic compounds, i.e., the biomarkers, making it possible to indirectly measure microbial contamination in foodstuff. Herein, highly ordered mesoporous tungsten oxides with high surface areas and tunable pores have been synthesized and used as sensing materials to achieve an exceptionally sensitive and selective detection of trace Listeria monocytogenes. The mesoporous WO-based chemiresistive sensors exhibit a rapid response, superior sensitivity, and highly selective detection of 3-hydroxy-2-butanone. The chemical mechanism study reveals that acetic acid is the main product generated by the surface catalytic reaction of the biomarker molecule over mesoporous WO. Furthermore, by using the mesoporous WO-based sensors, a rapid bacteria detection was achieved, with a high sensitivity, a linear relationship in a broad range, and a high specificity for Listeria monocytogenes. Such a good gas sensing performance foresees the great potential application of mesoporous WO-based sensors for fast and effective detection of microbial contamination for the safety of food, water safety and public health.

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