Science Daily March 12, 2020 Researchers at UC San Diego have developed a novel separator design for lithium batteries to mitigate the effects of an internal short circuit by limiting the self‐discharge current to prevent cell temperature rise. A nano‐composite Janus separator with a fully electronically insulating side contacting the anode and a partially electronically conductive (PEC) coating with tunable conductivity contacting the cathode is implemented to intercept dendrites, control internal short circuit resistance, and slowly drain cell capacity. They demonstrated that Li‐metal batteries with the Janus separator perform normally before shorting, which then results in a gradual increase of […]
Tag Archives: Lithium battery
Scientists develop a lithium-ion battery that won’t catch fire
Phys.org October 18, 2019 Current Li-ion batteries are susceptible to catastrophic fire and explosion incidents because they are built with flammable and combustible materials. Researchers at Johns Hopkins University have built a new class of “water-in-salt” and “water-in-bisalt” electrolytes—referred to as WiS and WiBS, respectively—that, when incorporated in a polymer matrix, reduces water activity and elevates the battery’s energy capabilities and life cycle while ridding it of the flammable, toxic, and highly reactive solvents present in current Li-ion batteries. It expands the electrochemical stability window to 4.1 V, dramatically improves cycle life in full cells with lithium titanate anodes compared […]
Graphene coating could help prevent lithium battery fires
Science Daily April 9, 2019 A team of researchers in the US (University of Illinois, Texas A&M, Argonne National Laboratory) has shown that an atomically thin layer of reduced graphene oxide can suppress oxygen release from LixCoO2 particles and improve their structural stability. They showed that the reduction of Co species from the graphene‐coated samples is delayed when compared with bare cathodes, the rGO layers could suppress O2 formation more effectively due to the strong COcathode bond formation at the interface of rGO/LCO where low coordination oxygens exist. This investigation uncovers a reliable approach for hindering the oxygen release reaction […]
Chemists make breakthrough on road to creating a rechargeable lithium-oxygen battery
Phy.org August 23, 2018 Two of the more serious issues with Lithium – Oxygen battery involve the cell chemistry of (superoxide, LiO2) and the peroxide product (Li2O2) reacting with the porous carbon cathode, degrading the cell from within. And the superoxide consumes the organic electrolyte in the process, which greatly limits the cycle life. Researchers in Canada switched the organic electrolyte to a more stable inorganic molten salt and the porous carbon cathode to a bifunctional metal oxide catalyst. By operating the battery at 150 C, they found that the more stable product Li2O is formed instead of Li2O2. This […]
Researchers predict materials to stabilize record-high capacity lithium-ion battery
Science Daily May 29, 2018 In 2016 a French research team reported that by replacing cobalt with manganese more than doubles the battery capacity but performance degraded significantly. A team of researchers in the US (Northwestern University, MIT) found that the reason behind the material’s high capacity was because oxygen participates in the reaction process. They predicted that mixing chromium or vanadium with lithium-manganese-oxide will produce stable compounds that maintain the cathode’s unprecedented high capacity. They will experimentally test these theoretical compounds in the laboratory…read more. Open Access TECHNICAL ARTICLE
Surprising discovery could lead to better batteries
Science Daily January 12, 2018 When a lithium-ion battery supplies electricity, lithium ions flow into empty sites in the atomic lattice. It was assumed that the concentration of lithium would continuously increase in the lattice. By imaging reactions inside the electrodes in real time, an international team of researchers (USA – Brookhaven National Laboratory, University of Michigan, MIT, UC Berkeley, UK, China) has shown that, when the battery’s electrodes are made from nano-sized particles, the lithium concentration within local regions of nanoparticles go up, and then down. This discovery is a major step toward improving the battery life of consumer […]