A step on the way to solid-state batteries

Nanowerk   October 24, 2023 Researchers at MIT have introduced Li-garnet Li7La3Zr2O12−d (LLZO) as a suitable ceramic due to its high Li+ conductivity and wide electrochemical stability window. However, high sintering temperatures raise concerns about the cathode interface stability, production costs, and energy consumption for scalable manufacture. They developed a “sinter-free” route to stabilize cLLZO as films at half of its sinter temperature. They established a time-temperature-transformation (TTT) diagram which captured the amorphous-to-crystalline LLZO transformation based on crystallization enthalpy analysis and confirmed stabilization of thin-film cLLZO at record low temperatures of 500 °C. According to the researchers their findings pave the way […]

Revolutionizing lithium production on a string

Science Daily   September 7, 2023 A team of researchers in the US (Princeton University, University of Maryland) has developed an efficient and self-concentrating crystallization method for the selective extraction of lithium from both brine and seawater. The sequential and separable crystallization of cation species with different concentrations and solubilities was enabled by a twisted and slender 3D porous natural cellulose fibre structure via capillary and evaporative flows. The process exhibited an evaporation rate as high as 9.8 kg m−2 h−1, and it selectively concentrated lithium by orders of magnitude. They characterized the composition and spatial distribution of crystals, and a transport model deciphered […]

Tiny movements, deep inside a battery

Nanowerk  April 5, 2023 Researchers at Argonne National Laboratory demonstrated lithiation gradients and electrode assembly movement during electrochemical cycling of a Li-metal cell containing a Ni–Mn–Co layered oxide cathode (NMC811). During charge, deposition of Li+ ions from the cathode increased the Li foil thickness; during discharge, the thickness decreased as Li+ ions are stripped off the foil. The resulting periodic movement was observed through tracking of Bragg peaks from the ordered phases of the cathode and separator. In addition to this 3.6 μm/mAh displacement, continuous mossy Li build-up on the anode caused an irreversible drift of the assembly, which is […]

Carbon fiber paper for longer-lasting electric vehicle batteries

Nanowerk  March 27, 2023 Researchers in South Korea have designed and constructed a hierarchical surface on carbon fiber (CF) using binders in fabricated CF paper (CFP). The lightweight CF with high mechanical properties established a 3D network structure as an alternative to Cu foil. The binders were transformed into oxygen-containing amorphous carbon and sodium carbonate (Na2CO3) using a low-temperature carbonization process which to uniform Li nucleation and a stable solid electrolyte interphase layer with inorganic components. In tests CFP with amorphous carbon and Na2CO3 (ANCFP) showed a low Li nucleation overpotential and smooth dendrite-free Li plating. The ANCFP electrode exhibited […]

Stalactites and stalagmites in the battery?

Science Daily  March 17, 2023 The role of grain boundaries in the nucleation and dendritic growth of metallic lithium is not yet fully understood. Researchers in Germany used operando Kelvin probe force microscopy measurements to map locally time-dependent electric potential changes in the Li6.25Al0.25La3Zr2O12 garnet-type solid electrolyte. They found that the Galvani potential dropped at grain boundaries near the lithium metal electrode during plating as a response to the preferential accumulation of electrons. Time-resolved electrostatic force microscopy measurements and quantitative analyses of lithium metal formed at the grain boundaries under electron beam irradiation supported this finding. Based on these results, […]

3D battery imaging reveals the secret real-time life of lithium metal cells

Science Daily  March 9, 2023 An international team of researchers (Sweden, Denmark, Switzerland) succeeded in observing how the lithium metal in the cell behaves as it charges and discharges. They developed an operando synchrotron X-ray tomographic microscopy method capable of probing in real-time the formation, growth, and dissolution of Li microstructures during the cycling of a Li||Cu cell containing a standard non-aqueous liquid electrolyte solution. This enabled tracking the evolution of deposited Li metal as a function of time and applied current density and distinguishing the formation of electrochemically inactive Li from the active bulk of Li microstructures. Now the […]

New design for lithium-air battery could offer much longer driving range compared with the lithium-ion battery

Science Daily  February 22, 2023 Lithium-air batteries have scope to compete with gasoline in terms of energy density. However, in most systems, the reaction pathways either involve one- or two-electron transfer, leading to lithium peroxide (Li2O2) or lithium superoxide (LiO2), respectively. A team of researchers in the US (Illinois Institute of Technology, Argonne National Laboratory, Illinois University) used a composite polymer electrolyte based on Li10GeP2S12 nanoparticles embedded in a modified polyethylene oxide polymer matrix. They found that Li2O is the main product in a room temperature solid-state lithium-air battery. The battery was rechargeable for 1000 cycles with a low polarization […]

Lithium-sulfur batteries are one step closer to powering the future

Science Daily  January 6, 2023 Lithium-sulfur batteries exhibit poor cycle life and low energy content due to the polysulfides shuttling during cycling. An international team of researchers (South Korea, USA – Argonne National Laboratory, Stanford University) developed redox-active interlayers consisting of sulfur-impregnated polar ordered mesoporous silica. Unlike the redox-inactive interlayers, these redox-active interlayers enabled the electrochemical reactivation of the soluble polysulfides, protected the lithium metal electrode from detrimental reactions via silica-polysulfide polar-polar interactions and increased the cell capacity. When tested in a non-aqueous Li-S coin cell configuration, the use of the interlayer enabled an initial discharge capacity of about 8.5 […]

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 […]

Novel method helps quantify reversibility and irreversibility of practical Li metal batteries

Phys.org  October 4, 2022 Accurate assessment of the reversibility of electrodes is crucial for battery performance evaluations. However, it is challenging to acquire the true reversibility of the Li anode in lithium-metal batteries, mainly because an excessive amount of Li is commonly used. An international team of researchers (China, USA – UC San Diego, University of Chicago) proposed an analytic approach to quantitatively evaluate the reversibility of practical lithium-metal batteries. They identified key parameters that govern the anode reversibility and subsequently established their relationship with the cycle number by considering the mass of active and inactive Li of the cycled […]