RESUMO
Here we show the electrochemical data for a Ferroelectric Electrolyte Battery (FEB) Li/ferroelectric Li-glass electrolyte (Li2·99Ba0·005ClO) in cellulose/γ-MnO2 pouch-cell with (2.5 × 2.5 cm2) discharged with a green LED load. The Li2·99Ba0·005ClO electrolyte was synthesized and ground in ethanol. A cellulose matrix was dipped into the Li-glass/ethanol slurry. The γ-MnO2 based cathode was doctor bladed onto a carbon-coated aluminum foil current collector. The cell was assembled in an Ar-filled glove-box and it was not sealed and, therefore, it remained inside the glove-box while discharging with a green LED at approximately 24 °C for 334 days (>11 months) corresponding to 764 mAhg-1 of the active cathode and to 224 mAhg-1 of the electrolyte. The maximum capacity of γ-MnO2 is 209 mAhg-1 and of the MnO2 in the commercial cell is 308 mAhg-1, corresponding to LiMnO2; therefore, the capacity of the FEB is 370% the capacity of the γ-MnO2 and 250% the capacity of the MnO2 in the commercial cell. Moreover, the experimental capacity of the electrolyte minus the maximum capacity of the γ-MnO2 is 163 mAhg-1 of the electrolyte. The potential difference between anode and cathode in a diode is non-linear and dependent on the input current and, therefore, the plateaus in the potential vs time curves do not correspond to thermodynamic equilibria of the electrochemical cell energy source. Nevertheless, the maximum output current as well as the FEB cell's discharge profile may be determined with an LED and compared with traditional battery cells' profiles. The present data might be used by the electrochemical (in particular, battery), electrostatic and ferroelectric materials researchers and industrials for comparative analysis. Furthermore, it can be reused to calculate the maximum energy stored electrostatically in these devices.
RESUMO
Here we show the electrochemical raw data for a Li/ferroelectric Li-glass electrolyte/plasticizer/Li-rich, F doped LNMO coin cell where the plasticizer is succinonitrile-SN. The nominal composition of the active oxide-host cathode particles is Li1.36Ni0.49Mn1.15O3.28F0.36 (LNMO) that disproportionated into 78 wt% spinel phase LiNi1/2Mn3/2O3.8F0.2 and 22 wt% Li-rich, F-doped layered phase containing Li2MnO3 planes separated by Li+ and Ni2+ ions. The Li2.99Ba0.005OCl electrolyte was synthesized and ground in ethanol. A cellulose matrix was dipped into the glass/ethanol slurry. This cell has been cycling for two years and six months. The electrochemical performance was firstly published in graphs after cycling the cell for about one year and three months [1]. The Li//LNMO CR2032 coin cell was assembled in an argon-filled glove box and electrochemically tested in a battery testing analyzer (LAND) at room temperature and at constant specific current densities and potentials between 2.5 and 4.8 V. Moreover, the cell's cycling current is 23 mA g-1 (active cathode). The data might be used by the electrochemical (in particular, battery), electrostatic and ferroelectric researchers and industrials for comparative analysis. Furthermore, it can be reused by anyone interested in solid-state devices that wants to calculate the maximum energy stored electrostatically in these devices.
RESUMO
Materials having a high dielectric constant are needed for a variety of electrical applications from transistors to capacitors. Ferroelectric amorphous-oxide (glass) alkali-ion electrolytes of composition A2.99Ba0.005ClO (A = Li, Na) are shown by two different types of measurement and different consistent analyses to have extraordinarily high dielectric constants, varying from 109 at 25 °C to 1010 at 220 °C if the glass is properly conditioned. These anomalously high dielectric properties coexist with alkali-ion conductivities at 25 °C that are equivalent to those of the best organic-liquid electrolytes of a Li-ion cell, and cyclic voltammetry (CV) in a Au/glass electrolyte/Au cell is stable from -10 to +10 V. A model to interpret microscopically all the key features of the CV curves shows that the electric-double-layer capacitors that form at the gold/electrolyte interfaces in the Au/glass electrolyte/Au heterojunction reverse polarization at an applied voltage V = ±2.1 V, resulting in three almost equivalent discharging capacitances for a single physical capacitor from -10 to +10 V.
RESUMO
A room-temperature all-solid-state rechargeable battery cell containing a tandem electrolyte consisting of a Li+-glass electrolyte in contact with a lithium anode and a plasticizer in contact with a conventional, low cost oxide host cathode was charged to 5 V versus lithium with a charge/discharge cycle life of over 23,000 cycles at a rate of 153 mA·g-1 of active material. A larger positive electrode cell with 329 cycles had a capacity of 585 mAh·g-1 at a cutoff of 2.5 V and a current of 23 mA·g-1 of the active material; the capacity rose with cycle number over the 329 cycles tested during 13 consecutive months. Another cell had a discharge voltage from 4.5 to 3.7 V over 316 cycles at a rate of 46 mA·g-1 of active material. Both the Li+-glass electrolyte and the plasticizer contain electric dipoles that respond to the internal electric fields generated during charge by a redistribution of mobile cations in the glass and by extraction of Li+ from the active cathode host particles. The electric dipoles remain oriented during discharge to retain an internal electric field after a discharge. The plasticizer accommodates to the volume changes in the active cathode particles during charge/discharge cycling and retains during charge the Li+ extracted from the cathode particles at the plasticizer/cathode-particle interface; return of these Li+ to the active cathode particles during discharge only involves a displacement back across the plasticizer/cathode interface and transport within the cathode particle. A slow motion at room temperature of the electric dipoles in the Li+-glass electrolyte increases with time the electric field across the EDLC of the anode/Li+-glass interface to where Li+ from the glass electrolyte is plated on the anode without being replenished from the cathode, which charges the Li+-glass electrolyte negative and consequently the glass side of the Li+-glass/plasticizer EDLC. Stripping back the Li+ to the Li+-glass during discharge is enhanced by the negative charge in the Li+-glass. Since the Li+-glass is not reduced on contact with metallic lithium, no passivating interface layer contributes to a capacity fade; instead, the discharge capacity increases with cycle number as a result of dipole polarization in the Li+-glass electrolyte leading to a capacity increase of the Li+-glass/plasticizer EDLC. The storage of electric power by both faradaic electrochemical extraction/insertion of Li+ in the cathode and electrostatic stored energy in the EDLCs provides a safe and fast charge and discharge with a long cycle life and a greater capacity than can be provided by the cathode host extraction/insertion reaction. The cell can be charged to a high voltage versus a lithium anode because of the added charge of the EDLCs.