Nanowerk October 29, 2022 The lithium-metal batteries cycling encounters a low Coulombic efficiency (CE) due to the unceasing electrolyte decomposition. Improving the stability of solid electrolyte interphase (SEI) suppresses the decomposition and increases CE. However, SEI morphology and chemistry alone cannot account for CE, and a full explanation is still lacking. Researchers in Japan found that in diverse electrolytes, the large shift in the Li electrode potential and its association with the Li+ coordination structure influences the CE. Machine learning regression analysis and vibrational spectroscopy revealed that the formation of ion pairs is essential for upshifting the Li electrode potential, […]
Tag Archives: Lithium batteries
Flexible solid electrolytes for all-solid-state lithium batteries
Phys.org October 3, 2022 The thick electrolyte layer and rigid nature as well as poor interfacial contact of doped garnet-type solid electrolytes are obstacles for its application in all-solid-state lithium batteries. Through solvent-free procedure researchers in China developed an ultrathin flexible Li6.4La3Zr1.4Ta0.6O12- (LLZTO-) based solid electrolyte with 90 wt% LLZTO. The resulting film exhibited ultrahigh ionic conductance of 41.21 mS at 30°C, excellent oxidation stability of 4.6 V, superior thermal stability and nonflammability. The assembled Li||LiFePO4 pouch cell with integrated electrolyte/cathode interface exhibited excellent rate performances and cycle performances with a capacity retention of 71.4% from 153 mAh g-1 to 109.2 mAh g-1 at 0.1 C […]
Researchers unveil mystery inside lithium oxygen batteries
Phys.org September 30, 2022 Researchers in China prepared an integrated air electrode with highly ordered channels. They observed morphological composition and distribution of Li2O2 inside the real air electrode. The results showed that the toroidal Li2O2 was constrained by the channel size and exhibited a larger diameter on the separator side at high currents. The coupling effects of charge transfer impedance and concentration polarization on sudden death were analyzed in-depth at low and high currents. The growth model suggested that toroidal Li2O2 exhibited a high dependence on the electrode surface structure. They proposed a new route where the Li2O2/electrode interface […]
An innovative process prevents irreversible energy loss in batteries
Phys.org August 24, 2021 Due to the permanent loss of Li ions that occurs during the initial charge in the stabilization stage of the battery production the theoretical energy density that can be stored in the batteries has not been achieved. To overcome this issue researchers in South Korea have developed an electrode pre-treatment solution capable of minimizing the initial Li ion loss in graphite-silicon oxide composite anodes. After being dipped in the solution, the anode, which was composed of 50% SiOx, demonstrated negligible Li loss, enabling a full cell to exhibit near-ideal energy density. The work highlights the promise […]
Making batteries live longer with ultrathin lithium
Phys.org June 1, 2021 Lithium metal batteries (LMBs) have high energy density that exceeds lithium batteries (LIBs) by an order of magnitude. The key difference lies in the choice of anode material: LIBs use graphite leading to the formation of dendrites, whereas LMBs use lithium metal. Researchers in South Korea adopted a novel approach in which they pre-planted LiNO3 in the lithium metal powder (LMP) itself during the electrode fabrication process, allowing them to fabricate ~150-mm-wide and 20-μm-thick electrodes, which showed a coulombic efficiency of 96%. The addition of LiNO3 to LMP accomplished two things: it induced a uniform N-rich […]
Chemists develop a new technology to prevent lithium-ion batteries from catching fire
EurekAlert March 3, 2021 Researchers in Russia have developed a new approach to overcharge protection of Li-ion cells, which is provided by use of electrically conductive polymer that change electrical conductivity from conductive to insulating stage. A layer of the polymer deposited between the LiFePO4 -based cathode material and current collector acts as a chemical circuit breaker increasing the electrode resistance more than 20 times when the cell voltage exceeds 4.2 V. At 5 V overcharge it allows reversible charge-discharge of the cell without developing adverse process, while at 6 V overcharge it terminates the cell operation before electrolyte decomposition […]
Simple method for ceramic-based flexible electrolyte sheets for lithium metal batteries
EurekAlert April 11, 2020 The garnet-type ceramic Li7La3Zr2O12 (LLZO) is one of the few solid-state fast-ion conductors that is stable against Li metal. However, the densification of LLZO powders usually requires high sintering temperatures which likely results in Li loss and various side reactions. Researchers in Japan have developed a process to make flexible composite Al-doped LLZO (Al-LLZO) sheet electrolyte which can be mass-produced at room temperature. The sheet electrolyte enables Li-metal batteries to operate at both 60 and 30 °C, demonstrating its potential application for developing practical Li-metal batteries…read more. TECHNICAL ARTICLE
Thermal nanotransistor can conduct heat away from electronic components
Nanowerk November 14, 2018 An international team of researchers (USA – Stanford University, Rice University, UC Davis, SLAC National Accelerator Laboratory, Germany) bathed a thin layer of molybdenum disulfide that is made up of layered sheets of atoms in a liquid with lots of lithium ions to make it into a transistor-like switch. When a small electrical current is applied to the system, the lithium atoms begin to infuse into the layers of the crystal, changing its heat-conducting characteristics. As the lithium concentration increases, the thermal transistor switches off. Besides enabling dynamic heat control, the team’s results provide new insights […]
New carbon could signal step-change for the world’s most popular batteries
Phys.org June 25, 2018 An international team of researchers (China, India, UK, France) used ‘Eglinton homocoupling’ involving removing silicon from carbon-silicon groups to produce carbon to carbon links resulting in OSPC-1, an amorphous, very stable and highly conductive anode material for lithium-ion batteries. It does not form dendrites, able to store lithium ions at more than double the rate as graphite with high charging speeds and longer-lasting than graphite. They found no signs of deterioration after over 100 charging and discharging cycles. The method used by the team has the potential to be extended to other 3-D carbon materials… read […]