Science Daily December 7, 2022 The issues arising from the low S mass loading and poor cycling stability caused by the shuttle effect of polysulfides seriously limit the operating capacity and cycling capability of room-temperature sodium–sulfur (RT-Na/S) batteries. An international team of researchers (China, Australia) synthesized sulfur-doped graphene frameworks supporting atomically dispersed 2H-MoS2 and Mo1 (S@MoS2-Mo1/SGF) with a record high sulfur mass loading of 80.9 wt.% as an integrated dual active sites cathode for RT-Na/S batteries. They displayed unprecedented cyclic stability with a high initial capacity and a low-capacity fading rate of 0.05% per cycle over 1000 cycles. Experimental and […]
Category Archives: Battery technology
Flameproofing lithium-ion batteries with salt
Science Daily December 7, 2022 A team of researchers in the US (Stanford University, SLAC National Accelerator Laboratory, UC Berkeley) found that anchored solvent molecules can increase the ionic conductivity of the electrolyte without undermining its non-flammability. They developed a liquid-state polymer electrolyte composed of LiFSI salts, dimethoxyethane (DME) solvents, and polysiloxane tethered with ion-solvating moieties. DME coordinated with both the salt and the polymer, while, together with the salt, they synergistically plasticized the polymer to increase the ionic conductivity. The resulting non-flammable polymer electrolyte had a room-temperature ionic conductivity of 1.6 mS/cm and a wide operation window of 25°C–100°C. […]
Engineers solve a mystery on the path to smaller, lighter batteries
MIT News November 18, 2022 Whether dendrites are driven by mechanical failure or electrochemical degradation of solid electrolytes remains an open question. If internal mechanical forces drive failure, superimposing a compressive load that counters internal stress may mitigate dendrite penetration. A team of researchers in the US (MIT, Brown University) investigated this hypothesis by dynamically applying mechanical loads to growing dendrites in Li6.6La3Zr1.6Ta0.4O12 solid electrolytes. Operando microscopy revealed marked deflection in the dendrite growth trajectory at the onset of compressive loading. Sufficient loading the deflection averted cell failure. They quantified the impact of stack pressure and in-plane stresses on dendrite […]
Putting the brakes on lithium-ion batteries to prevent fires
Science Daily November 14, 2022 Researchers in China have developed a kind of novel shape-memorized current collector (SMCC), which can successfully brake battery thermal runaway at the battery internal overheating status. Unlike traditional current collectors made of commercial copper foils, SMCC is made of a micropatterned shape memory micron-sized film with copper deposition. SMCC displays ideal conductivity at normal temperatures and turns to be insulative at overheating temperatures. According to the researchers a battery consisting of an SMCC can run normally at temperatures lower than 90 °C, while it quickly achieves self-shutdown before the occurrence of battery combustion and explosion…read […]
The answer is in the sheets: 2D nanosheets as anodes in Li-ion batteries
Phys.org October 31, 2022 2D nanostructures based on transition-metal diborides (TMDs) are theoretically predicted to possess an exceptionally high rate and long cycling stability for Li-ion storage owing to the intrinsic presence of boron honeycomb planes and multivalent transition-metal atoms. An international team of researchers (Japan, India) investigated the Li-ion storage potential of the TMD-based nanostructure–titanium diboride (TiB2)-based hierarchical nanosheets (THNS). They demonstrated that THNS can be utilized as a high-rate anode material for Li-ion battery (LIB) and that a high discharge capacity can be obtained at a current rate of 0.025 A g1– galvanostatic charge/discharge. They demonstrated that the […]
Researchers design next-generation electrolytes for lithium batteries
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, […]
Stable sodium anodes for sodium metal batteries
Phys.org November 2, 2022 All-solid-state batteries are disadvantaged by their poor physical solid-solid interfacial contact and low ionic conductivity, which restrict their performance and hinder their short-term commercial applicability. Based on the interfacial protection strategy, researchers at UT Austin introduced fluoroethylene carbonate (FEC) into the PDOL system (1,3-Dioxolane (DOL) that can be polymerized through catatonically ring-opening reactions at room temperature to obtain poly(1,3-dioxolane). After the introduction of FEC, the accumulation of reaction products was reduced at the Na metal anode side prior to DOL addition, forming a NaF-rich passivation layer and inhibiting further side reactions between DOL and the Na […]
Battery tech breakthrough paves way for mass adoption of affordable electric car
Science Daily October 12, 2022 Using massive batteries to alleviate range anxiety is ineffective for mainstream EV adoption due to the limited raw resource supply and high cost. Fast charging enables downsizing of EV batteries for both affordability and sustainability, without causing range anxiety. However, fast charging of energy-dense batteries remains a challenge. A team of researchers in the US (Pennsylvania State College, State College (PA)) combined materials based on asymmetric temperature modulation with a thermally stable dual-salt electrolyte to achieve charging of a 265 Wh kg−1 battery to 75% (or 70%) state of charge in 12 (or 11) minutes for more […]
The battery that runs 630 km on a single charge
Science Daily October 6, 2022 Anode-free Li metal batteries can increase energy density beyond that of standard lithium-ion batteries. The absence of Li reservoir generates unwarranted volume expansion, permitting electrolyte depletion and rapid cathode capacity consumption. To address this issue researchers in South Korea developed an anode-free Li metal battery with an ion-conductive layer coated with Cu current collector Ag/L in typical carbonate-based electrolytes. The ion-conducting layer causes stable solid electrolyte interphase development and allows for minimal volume expansion when utilizing stable Li hosts. Via density functional theory calculation and experimental measurements and analysis, they demonstrated the beneficial effect of […]
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 […]