Various embodiments of the present technology may provide methods and apparatus for a battery. The apparatus may be configured to prevent leakage current from the battery to a number of sub-systems by selectively operating switches that connect the battery to the sub-systems. Operation of the switches may be based on whether the battery is charging or discharging and the capacity of the battery.

Various embodiments of the present disclosure describe energy storage devices. In one example, an energy storage device includes an anode having a plurality of active material particles, a cathode having a transition metal oxide material, and an electrolyte including a room temperature ionic liquid to couple the anode to the cathode. Each of the plurality of anode active material particles have a particle size of between about one micrometer and about fifty micrometers. One or more of the plurality of anode active material particles are enclosed by and in contact with a membrane coating permeable to lithium ions.

A method for determining a reference energy profile has comparing a first course and a second course. The first course describes an energy absorption of a first battery during a first charge cycle. The second course describes the energy absorption of the first or a second battery during a second charge cycle which follows after the first charge cycle. The comparison is performed for a plurality of time intervals. The method has determining a deviation between the first and the second course for each of the plurality of time intervals. In addition, the method has determining an amount of electrical energy based on the deviation for each of the time intervals, wherein the amount of electrical energy describes a preset default value of the reference energy profile for an amount of energy to be fed to a battery to be formed during a formation process of the battery to be formed for each of the time intervals.

A method for charging a lithium ion secondary battery of the present invention includes a first step and a second step. In the first step, A, B, and C satisfy the relationship A>B and B<C, where A represents an average charging current value in the range where a charge rate of the lithium ion secondary battery is 0% or more and less than 40%, B represents an average charging current value in the range where the charge rate is 40% or more and 60% or less, and C represents an average charging current value in the range where the charge rate is more than 60%. In the first step, the ratio of C.sub.MAX to C.sub.MIN (C.sub.MAX/C.sub.MIN) is 1.01 to 3.00, where C.sub.MAX represents the maximum value of the charging current value and C.sub.MIN represents the minimum value of the charging current value.

In a recovery control method for a secondary battery that includes a positive electrode containing a positive electrode active material, a solid electrolyte, and a negative electrode containing a negative electrode active material containing at least a lithium metal or a lithium alloy, and is fastened from an outside, the recovery control method includes: measuring cell resistance of the secondary battery; calculating a recovery limit resistance value indicating an upper limit value of resistance that ensures recovering the secondary battery from a depth of charge/discharge of the secondary battery, a cell temperature of the secondary battery, and a pressure applied to the secondary battery; and inhibiting charging/discharging the secondary battery and executing recovery control that recovers the secondary battery when a resistance value of the cell resistance is equal to or less than the recovery limit resistance value.

A method is provided for activating a secondary battery having a negative electrode, a positive electrode, and a microporous separator between the negative and positive electrodes permeated with carrier-ion containing electrolyte, the negative electrode having anodically active silicon or an alloy thereof. The method includes transferring carrier ions from the positive electrode to the negative electrode to at least partially charge the secondary battery, and transferring carrier ions from an auxiliary electrode to the positive electrode, to provide the secondary battery with a positive electrode end of discharge voltage V.sub.pos,eod and a negative electrode end of discharge voltage V.sub.neg,eod when the cell is at a predefined V.sub.cell,eod value, the value of V.sub.pos,eod corresponding to a voltage at which the state of charge of the positive electrode is at least 95% of its coulombic capacity and V.sub.neg,eod is at least 0.4 V (vs Li) but less than 0.9 V (vs Li).

A battery monitoring system continuously calculates the estimated runtime of a bank of batteries in a battery backup system during both a period of operation when the load current is supplied by a commercial source of AC power and during a period of operation when the commercial source of AC power is not present and the load current is supplied by the bank. The estimated runtime may be displayed to an operator and used to alert the operator if the cutoff voltage of a battery in the bank is at or near its cutoff voltage. The system may open a circuit breaker to avoid catastrophic damage before the cutoff voltage is reached.

A method of forming an active material for a positive electrode of a lithium-ion battery includes quenching a powder of the active material in water. The active material may include layered lithium rich nickel manganese oxide.

A vehicle-mounted device for detecting battery state comprises a controller, a load unit, and a switch unit. The load unit is coupled to the battery, the switch unit is coupled between the battery and the load unit. The controller can control the switch unit to disconnect or connect the battery and the load unit at a predefined frequency. The controller can switch the load unit to generate ripple voltage on the battery, and measure the ripple voltage of each battery cell, an abnormal state of a battery can be determined according to the ripple voltage of each battery cell.

A method for predicting an onset of a capacity fading in a battery includes measuring, over a period of time, a plurality of parameters related to charging and discharging cycles of the battery; detecting, based on the measured plurality of parameters, the onset of the capacity fade in the battery; and providing a notification on the electronic device indicating the detected onset of the capacity fade.