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 […]
Tag Archives: Lithium battery
It’s in the air – battery discovery takes up the charge
Science Daily February 10, 2022 An international team of researchers (Australia, China, USA – Argonne National Laboratory) describe the details of an Li-O2 battery operated via a new quenching/mediating mechanism that relies on the direct chemical reactions between a versatile molecule and superoxide radical/Li2O2. The battery exhibits a 46-fold increase in discharge capacity, a low charge overpotential of 0.7 V, and an ultralong cycle life greater than 1400 cycles. Redox-active 2,2,6,6-tetramethyl-1-piperidinyloxy moieties bridged by a quenching-active perylene diimide backbone acts as a redox mediator to catalyze discharge/charge reactions and serves as a reusable superoxide quencher to chemically react with superoxide […]
Light could boost performance of fuel cells, lithium batteries and other devices
Phys.org January 14, 2022 In solid electrolytes the ionic conductivity is often markedly degraded by the fact that the ions get blocked at the crystallite grains boundaries. An international team of researchers (Spain, Germany, USA – MIT, Japan) has shown how light can be used to lower the barrier height that ions encounter at grain boundaries and enhance the flow of the ions by orders of magnitude by optimizing the system. They demonstrated the effect of light on the movement of oxygen ions through solid electrolyte composed of ceria and gadolinium. According to the researchers the process can be applied […]
Revitalizing batteries by bringing ‘dead’ lithium back to life
Science Daily January 4, 2022 Because i-Li loses electrical connection with the current collector, it has been considered electrochemically inactive or ‘dead’ in batteries. A team of researchers in the US (Stanford University, SLAC National Accelerator Laboratory) showed that i-Li is highly responsive to battery operations, owing to its dynamic polarization to the electric field in the electrolyte. Simultaneous Li deposition and dissolution occurs on two ends of the i-Li, leading to its spatial progression toward the cathode (anode) during charge (discharge). Through their results they showed that the progression rate of i-Li is mainly affected by its length, orientation, […]
Ultrafast charging of batteries using fully new anode material
Nanowerk November 15, 2021 Nanosizing of active electrode material is a common strategy to increase the effective lithium-ion diffusion transport rate, but it also decreases the volumetric energy/power density and stability of the battery. An international team of researchers (the Netherlands, China, Germany) has demonstrated nickel niobate (NiNb2O6) as a new intrinsic high-rate anode material for lithium-ion batteries without the requirement of realizing nano-architectures. The NiNb2O6 host crystal structure exhibits only a single type of channel for lithium-ion intercalation and can be fully lithiated with a capacity of about 244 mAh g−1 at low current densities. A high diffusion coefficient […]
The hidden culprit killing lithium-metal batteries from the inside
EurekAlert July 14, 2021 A team of researchers in the US (Sandia National Laboratory, University of Oregon, industry, Lawrence Berkeley National Laboratory) repeatedly charged and discharged lithium coin cells with the same high-intensity electric current that electric vehicles need to charge. Using cryogenic femtosecond laser cross sectioning and subsequent scanning electron microscopy, they observed the electroplated Li-metal morphology and the accompanying solid electrolyte interphase (SEI) into and through the intact coin cell battery’s separator, gradually opening pathways for soft-short circuits that cause failure. They found that separator penetration by the SEI guided the growth of Li dendrites through the cell. […]
The Lithium-Ion Battery With Built-In Fire Suppression
IEEE Spectrum October 22, 2020 To make lithium-ion batteries lighter, safer and more efficient a team of researchers in the US (Stanford University, SALC National Accelerators Laboratory) redesigned current conductors, thin metal foils that distribute current to and from electrodes, by replacing the all-copper conductor middle, with a layer of lightweight polymer coated in ultrathin copper and embedded fire retardant in the polymer layer to quench flames. The polymer makes the current collector 80 percent lighter, leading to an increase in energy density from 16 to 26 percent. Whenever the battery has combustion issues, the fire retardant embedded inside the […]
New insights into lithium-ion battery failure mechanism
Science Daily August 25, 2020 Ni-rich layered cathode materials are among the most promising candidates for high-energy-density Li-ion batteries, yet their degradation mechanisms are still poorly understood. Researchers in the UK found that as the battery materials expand and shrink the lithium ions move in and out. With prolonged use the atoms at the surface of the material had rearranged to form new structures that are no longer able to store energy. The areas of reconstructed surface apparently act as stakes that pin the rest of the material in place and prevent it from the contraction which is required to […]
Thin layer protects battery, allows cold charging
Science Daily August 26, 2020 Stable operation of rechargeable lithium-based batteries at low temperatures is plagued by dendritic Li plating and unstable solid–electrolyte interphase (SEI). A team of researchers in the US (Pennsylvania State University, Argonne National Laboratory, Ohio University, University of Illinois) used a self-assembled monolayer of electrochemically active molecules on current collectors that regulates the nanostructure and composition of the SEI and deposition morphology of Li metal anodes to achieve high performance. A multilayer SEI that contains a lithium fluoride-rich inner phase and amorphous outer layer effectively seals the Li surface, in contrast to the conventional SEI, which […]
Stretchable lithium-ion battery is based on new micro-honeycomb structure
Nanowerk April 29, 2020 In stretchable batteries the electrodes must have a degree of stretchability because the active materials occupy most of the volume, and the separator and packaging should also be stretchable. Researchers in South Korea have developed an all-component stretchable lithium-ion battery by leveraging the structural stretchability of re-entrant micro-honeycomb graphene–carbon nanotube (CNT)/active material composite electrodes and a physically cross-linked gel electrolyte, without using an inactive elastomeric substrate or matrix. Active materials interconnected via the entangled CNT and graphene sheets provided a mechanically stable porous network framework consisting solely of binder-free, highly conductive materials which provided superior electron […]