Electric Technology For Vehicles
ETV battery technology is based on High Voltage
Nickel-Manganese-Oxide (Spinel) cathode material. This material boasts fast
kinetics and structural stability, ensuring a combination of high power, high energy, and
safety, while maintaining a relatively low cost. Its high cell voltage (4.65V
vs. 3.2-3.7V SOTA) and stable profile provide added value in reduced
weight, volume, and cost of the battery pack.
batteries introduced in the early 1990s continue to be the energy storage
backbone of today's portable electronics.
High voltage - Spinel advantages
Substantial research points to high voltage Spinel oxides as promising new electrode candidates. However, their high voltage has detrimental effects which until now have thwarted their implementation in commercial batteries. ETV Energy is working toward mitigating these effects in order to make a commercially viable product that effectively utilizes Spinel's outstanding features.
voltage not only increases the energy and power densities [E(Wh/kg) = Ah/kg x
V; P(W/kg) = A/kg x V] but also reduces the number of cells per battery pack.
Given that EV batteries have high voltages (typically 300-600V), they are comprised of many cells connected in series. Implementing 4.7 volt cells in place of
conventional 3.2 volt or 3.7 volt cells reduces the overall number of cells by
Furthermore, since all LIB packs require battery management (BMS) and heat management
systems (HMS), reducing the number of cells per battery pack significantly
reduces the weight, volume and cost of the battery pack. Thus high-voltage Spinel systems deliver extra value by reducing the BMS and heat
management circuitry overhead.
While the characteristics of the LiCoO2/Graphite electrochemical system are acceptable for the portable electronics market, significant improvements in the safety, cost, specific energy and lifetime of lithium-ion must be made in order for large-scale lithium-ion batteries to become a viable solution for vehicle propulsion.
At the present time, the LiFePO4/Graphite electrochemical couple offers the most promise as it provides power, safety and cycle life beyond those of mature cobalt-based systems.
Although LiFePO4 has many advantages, it suffers from low potential (3.3 volt, vs. Li+/Li), and low material density (3.6 g cm−3). Batteries based on this cathode have relatively low energy-density; approximately 50% that of cobalt-based system.
Therefore, new battery systems that provide the most efficient combination of
performance, safety and cost are in great demand.
Field tests of prototype 9.2V
batteries (2S/1.7Ah battery)