The storage of electrical energy at high charge and discharge rate is an important technology in today's society, and can enable hybrid and plug-in hybrid electric vehicles and provide back-up for wind and solar energy. It is typically believed that in electrochemical systems very high power rates can only be achieved with supercapacitors, which trade high power for low energy density as they only store energy by surface adsorption reactions of charged species on an electrode material. Here we show that batteries which obtain high energy density by storing charge in the bulk of a material can also achieve ultrahigh discharge rates, comparable to those of supercapacitors. We realize this in LiFePO(4) (ref. 6), a material with high lithium bulk mobility, by creating a fast ion-conducting surface phase through controlled off-stoichiometry. A rate capability equivalent to full battery discharge in 10-20 s can be achieved.

Battery materials for ultrafast charging and discharging

Recent advances in all-solid-state rechargeable lithium batteries

The worldwide thirst for portable consumer electronics in the 1990s had an enormous impact on portable power. Lithium ion batteries, in which lithium ions shuttle between an insertion cathode (e.g., LiCoO2) and an insertion anode (e.g., carbon), emerged as the power source of choice for the highperformance rechargeable-battery market. The performance advantages were so significant that lithium ion batteries not only replaced Ni-Cd batteries but left the purported successor technology, nickel-metal hydride, in its wake.1 The thick metal plates of * To whom correspondence should be addressed. J.W.L: e-mail, jwlong@ccs.nrl.navy.mil; telephone, (+1)202-404-8697. B.D.: e-mail, bdunn@ucla.edu; telephone, (+1)310-825-1519. D.R.R.: e-mail, rolison@nrl.navy.mil; telephone, (+1)202-767-3617. H.S.W.: e-mail, white@chem.utah.edu; telephone, (+1)810-585-6256. † Naval Research Laboratory. ‡ UCLA. § University of Utah. 4463 Chem. Rev. 2004, 104, 4463−4492

Three-dimensional battery architectures.

Thin-Film Lithium and Lithium-Ion Batteries

Tremendous efforts have been dedicated into the development of high-performance energy storage devices with nanoscale design and hybrid approaches. The boundary between the electrochemical capacitors and batteries becomes less distinctive. The same material may display capacitive or battery-like behavior depending on the electrode design and the charge storage guest ions. Therefore, the underlying mechanisms and the electrochemical processes occurring upon charge storage may be confusing for researchers who are new to the field as well as some of the chemists and material scientists already in the field. This review provides fundamentals of the similarities and differences between electrochemical capacitors and batteries from kinetic and material point of view. Basic techniques and analysis methods to distinguish the capacitive and battery-like behavior are discussed. Furthermore, guidelines for material selection, the state-of-the-art materials, and the electrode design rules to advanced electrode are proposed.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/advs.201700322

Advanced Energy Storage Devices: Basic Principles, Analytical Methods, and Rational Materials Design.

Thin-film rechargeable lithium batteries with amorphous and crystalline LiCoO{sub 2} cathodes were investigated. The lithium cobalt oxide films were deposited by radio-frequency (RF) magnetron sputtering of an LiCoO{sub 2} target in a 3:1 Ar/O{sub 2} mixture gas. From proton-induced {gamma}-ray emission analysis (PIGE) and Rutherford backscattering spectrometry (RBS), the average composition of these films was determined to be Li{sub 1.15}CoO{sub 2.16} or, within experimental uncertainty, LiCoO{sub 2} + 0.08 Li{sub 2}O. The X-ray powder diffraction patterns of films annealed in air at 500 to 700 C were consistent with the regular hexagonal structure observed for crystalline LiCoO{sub 2}. The discharge curves of the cells with amorphous LiCoO{sub 2} cathodes showed no obvious structural transition between 4.2 and 2.0 V, while the discharge curves of the cells with polycrystalline cathodes were consistent with a two-phase potential plateau at {approximately}3.9 V with a relatively large capacity. Two lower capacity plateaus were observed at {approximately} 4.2 and 4.1 V with the 600 and 700 C annealed cathodes; the {minus}dq/dV peaks were broader and weaker for the 600 C annealed cathodes and were not present at all with the 500 C annealed films. The chemical diffusion coefficients of Li{sup +} in the cathodes obtainedmore » from ac impedance measurements at cell potentials of {approximately} 4 V ranged from {approximately} 10{sup {minus}12} cm{sup 2}/s for the as-deposited amorphous cathodes to {approximately} 10{sup {minus}9} cm{sup 2}/s for the films annealed at 700 C. The capacity loss on extended cycling of the thin-film cells varied with the crystallinity and thickness of the cathodes and with temperature. With the highly crystalline, 700 C annealed material, losses on cycling between 4.2 and 3.8 V at 25 C ranged from 0.0001%/cycle (> 10{sup 4} cycles) to 0.002%/cycle for cells with cathodes form 0.05 to 0.5 {micro}m thick.« less

Characterization of Thin‐Film Rechargeable Lithium Batteries with Lithium Cobalt Oxide Cathodes

Synthesis, Crystal Structure, and Ionic Conductivity of a Polycrystalline Lithium Phosphorus Oxynitride with the γ-Li3PO4 Structure

Lithium phosphorus oxynitride glasses with different lithium contents have been prepared by melting base glasses at high temperature in a flowing ammonia atmosphere for 16–72 h. The melt was then furnace-cooled to room temperature to avoid bubble formation in the sample. The structure of the lithium phosphorus oxynitride glasses was probed by X-ray photoelectron spectroscopy and high performance liquid chromatography. The results of ac impedance measurements show that nitrogen incorporation into the glass structure increases the ionic conductivity. The highest conductivity was found in Li0.99PO2.55N0.30 glass with σ ∼ 3.0 × 10−7 S cm−1 at 25°C and Ea = 0.60 eV.

Ionic conductivities and structure of lithium phosphorus oxynitride glasses

Expanded perlite products having controlled particle size distribution, methods of producing the expanded perlite products, and methods of use thereof are provided. The expanded perlite product has, for example, a low ratio of standard deviation of particle size distribution to median particle size (for example, less than 0.63) and low median particle size (for example, less than 50 microns). The expanded perlite product may be used in a variety of applications including filter applications.

Perlite products with controlled particle size distribution

Micronized perlite filler product, methods of producing the micronized expanded perlite products, and methods of use thereof are provided. The micronized expanded perlite product has, for example, a small median particle size (for example, less than 11 microns), a high blue light brightness (for example, higher than 84) and low oil absorption (for example, less than 70 percent in volume). The micronized expanded perlite product may be used in a variety of applications such as anti-block filler in plastic films and reinforcement filler in polymers.

Bo Wang

Papers

Characterization of Thin‐Film Rechargeable Lithium Batteries with Lithium Cobalt Oxide Cathodes

Synthesis, Crystal Structure, and Ionic Conductivity of a Polycrystalline Lithium Phosphorus Oxynitride with the γ-Li3PO4 Structure

Ionic conductivities and structure of lithium phosphorus oxynitride glasses

Perlite products with controlled particle size distribution

Micronized perlite filler product