Nanowerk September 28, 2021 Researchers in South Korea have made a structure with individual, overlapping units, similar to snake scales that can be used to construct shape-morphing batteries for untethered soft robots. They created it by folding well-defined, two-dimensional patterns with cutouts, the folding lines mimicking the hinge structure of snakeskin, enabling stable deformations without mechanical damage to rigid cells. The structure is applied to a stretchable Li-ion battery, constructed to form an arrangement of electrically interconnected, hexagonal pouch cells. Simulation confirmed that the battery maintains its performance under dynamic deformation with a 90% stretching ratio and 10-mm-radius bending curve, […]
Category Archives: Battery technology
High-rate magnesium rechargeable batteries move one step closer to realization
Science Daily August 23, 2021 Mg/S batteries are some of the most promising rechargeable batteries owing to their high theoretical energy density. However, their development is hindered by low electronic conductivity of S, sluggish Mg2+ diffusion in solid Mg–S compounds formed by discharge, and dissolubility of polysulfides into electrolytes. To address these problems researchers in Japan proposed liquid-S/sulfide composite cathode materials in combination with an ionic liquid electrolyte at intermediate temperatures (∼150 °C). The composite structure is spontaneously fabricated by electrochemically oxidizing metal sulfides, yielding liquid S embedded in a porous metal-sulfide conductive frame. They demonstrated the concept by a […]
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 […]
New salts raise the bar for lithium ion battery technology
Phys.org August 16, 2021 Lithium battery materials, currently in use, fall short in terms of safety and performance holding back the next generation of high-performance batteries. In particular, the development of the electrolyte poses a key challenge for higher power batteries suitable for energy storage and vehicle applications. Researchers in Australia have synthesized safe fluoroborate salts with battery grade purity by recrystallisation process. When put in a lithium battery with lithium manganese oxide cathodes, the cell cycled for more than 1000 cycles, even after atmospheric exposure. The salt was found to be very stable on aluminum current collectors at higher […]
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. […]
Preventing oxygen release leads to safer high-energy-density batteries
Phys.org July 13, 2021 Oxide-based cathode materials are key components of secondary batteries. Problems originating from the lattice oxygen instability in oxide-based intercalation cathodes are widely reported, such as capacity degradation, gas generation, and thermal runaway, highlighting the importance of deep insights into the critical factors for lattice oxygen stability. Researchers in Japan Investigated the lattice oxygen stability in layered rock-salt LiNi1/3Co1/3Mn1/3O2−δ with a focus on oxygen release behavior and relevant changes in crystal and electronic structures. Release of lattice oxygen facilitates cation mixing, transition metal slab expansion, and Li slab contraction, thus deteriorating the layered structure. In the beginning […]
Innovative batteries put flying cars on the horizon
EurekAlert June 7, 2021 Researchers at the Pennsylvania State University are exploring the requirements for electric vertical takeoff and landing (eVTOL) vehicles and designing and testing potential battery power sources. eVTOL’s unique operating profiles and requirements present grand challenges to batteries. The team’s work identifies the primary battery requirements for eVTOL in terms of specific energy and power, fast charging, cycle life, and safety, revealing that eVTOL batteries have more stringent requirements than electric vehicle batteries in all aspects. They found that fast charging is essential for downsizing aircraft and batteries for low cost while achieving high vehicle utilization rates […]
The biodegradable battery that’s 3D printed, disposable and made of paper
Phys.org June 3, 2021 A team of researchers in Switzerland developed and implemented the concept of a biodegradable electricity storage device. They developed gelatinous inks which consists of cellulose nanofibers and cellulose nanocrystallites, carbon in the form of carbon black, graphite and activated carbon. They used glycerin, water and two different types of alcohol to mix the ingredients and a pinch of table salt for ionic conductivity. They built a functioning supercapacitor from four layers of these ingredients flowing from a 3D printer one after the other: a flexible substrate, a conductive layer, the electrode and finally the electrolyte. The […]
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 […]
Rechargeable cement-based batteries
Science Daily May 18, 2021 Researchers in Sweden have developed a rechargeable cement-based battery using iron and zinc as anodes, and nickel-based oxides as cathodes. The conductivity of cement-based electrolytes was modified by adding short carbon fibers. The electrodes were produced by two methods: powder-mixing and metal-coating. Different combinations of cells were tested. The results showed that the best performance of the rechargeable battery was the Ni–Fe battery, produced by the metal-coating method. The battery has an average energy density of 7 Wh/m2 (or 0.8 Wh/L) during six charge/discharge cycles. Their battery could be more than ten times that of […]