Project

Vii: A Calorimeter can be used to measure the safety of batteries by simulating both normal and worst-case operating conditions safely under laboratory conditions. These techniques include differential scanning calorimetry, thermogravimetric analysis, explosion severity, and accelerating rate calorimetry.

Mechanical testing includes both static and dynamic testing of batteries, battery cases, and related components. The test consists of, for example, a tensile test, pressure test, fatigue test, impact test, creep test, and internal pressurization of batteries.

Here are the most common battery test methods:

Voltage test: Battery voltage reflects state-of-charge in an open circuit condition when rested. Voltage alone cannot estimate battery state-of-health (SoH).

Ohmic test: Measuring internal resistance identifies corrosion and mechanical defects when high. Although these anomalies indicate the end of battery life, they often do not correlate with low capacity. The ohmic test is also known as impedance test.

Full cycle test:A full cycle consists of charge/discharge/charge to read the capacity of the chemical battery. This provides the most accurate readings and calibrates the smart battery to correct tracking errors, but the service is time consuming and causes stress.

Rapid test: Common test methods include time domain by activating the battery with pulses to observe ion-flow in Li-ion, and frequency domain by scanning a battery with multiple frequencies. Advanced rapid-test technologies require complex software with battery-specific parameters and matrices serving as lookup tables.

Coloumb counting:The Full Charge Capacity (FCC) of a smart battery provides coulomb count that relates to SoH. FCC readout is instant but the data gets inaccurate with use and the battery requires calibration with a full cycle.

Read- and charge: A charger featuring RAC technology reads battery SoC with a proprietary filtering algorithm and then counts the coulombs to fill the battery. RAC requires a onetime calibration for each battery model; cycling a good pack provides this parameter that is stored in the battery adapters. RAC technology is a Cadex development.

State of life indicator: The State-of-Life-Indicator estimates battery life by counting the total coulombs a battery can deliver in its life. A new battery starts at 100%; delivered coulombs decrease the number until the allotment is spent and a battery replacement is imminent. The full scale is set by calculating the coulomb count of 1 cycle based on the manufacturer’s specifications (V, Ah) and then by multiplying the number with the given cycle count. Developed by Cadex, SOLI can be used in wheelchairs, medical devices, traction and UPS, installed when new or added as retrofit. Wireless connectivity provides fleet management.

Battery recycling 

The contents of the batteries are exposed using a shredder or a high-speed hammer depending on battery size. The contents are then submerged in caustic (basic not acidic) water. This caustic solution neutralizes the electrolytes, and ferrous and non-ferrous metals are recovered.Making new batteries consume lots of energy. However, when you recycle old batteries, manufacturers spend less energy. By recycling, you keep the energy used in making new batteries.

First step of lead acid batteries is collection, crushing,then sorting , then sieving and the extraction.

Battery Thermal runaway

Thermal runaway often occurs from punctures and improper charging. To counter such fire hazards, the inventors used a thermal fluid that contains a flame retardant. A flame retardant is a compound that inhibits, suppresses, or delays the production of flames or prevents the spread of fire.

Use of active and passive damage initiotors: These initiators initiate cracking or voiding in electrodes upon impact. Such cracks and/or voids increase the internal impedance of the electrode reducing the heat generation associated with possible internal shorting. Such additives are known as cracks or voids initiators (CVIs).

Change the battery design for minimal impact: 

According to a patent filed by Tesla, the inventors discussed a battery design that provides a predictable pathway through a portion of the cell (e.g., the cell cap assembly) for the efficient release of the thermal energy that occurs during thermal runaway, thereby reducing the chances of a rupture in an undesirable location. Furthermore, the design maintains the functionality of the cell cap as the positive terminal of the cell, thereby having minimal impact on the manufacturability and maximum use in a variety of applications.