Batteries
Contents
Objectif
- obtenir des batteries au prix le plus bas possible, impliquant probablement un assemblage maison de cellules
- acquérir des connaissances dans le domaine des batteries, faire les choses selon les normes en vigueur, ne pas compromettre la sécurité
Applications
Batteries Lithium-ion
https://en.wikipedia.org/wiki/Comparison_of_battery_types
https://en.wikipedia.org/wiki/Lithium-ion_battery
Handheld electronics mostly use LIBs based on lithium cobalt oxide (LiCoO2), which offers high energy density, but presents safety risks, especially when damaged.
Lithium iron phosphate (LiFePO4), Lithium ion manganese oxide battery (LMnO or LMO) and lithium nickel manganese cobalt oxide (LiNiMnCoO2 or NMC) offer lower energy density, but longer lives and inherent safety. Such batteries are widely used for electric tools, medical equipment and other roles. NMC in particular is a leading contender for automotive applications.
Lithium nickel cobalt aluminum oxide (LiNiCoAlO2 or NCA) and lithium titanate (Li4Ti5O12 or LTO) are specialty designs aimed at particular niche roles.
The new lithium sulphur batteries promise the highest performance to weight ratio.
http://batteryuniversity.com/learn/article/types_of_lithium_ion
Formes
Li-ion cells (as distinct from entire batteries) are available in various shapes, which can generally be divided into four groups:
- Small cylindrical (solid body without terminals, such as those used in laptop batteries)
- Large cylindrical (solid body with large threaded terminals)
- Pouch (soft, flat body, such as those used in cell phones)
- Prismatic (semi-hard plastic case with large threaded terminals, such as vehicles' traction packs)
https://en.wikipedia.org/wiki/Lithium_polymer_battery
A lithium polymer battery, or more correctly lithium-ion polymer battery (abbreviated variously as LiPo, LIP, Li-poly and others), is a rechargeable battery of lithium-ion technology in a pouch format. Unlike cylindrical and prismatic cells, LiPos come in a soft package or pouch, which makes them lighter but also less rigid.
[...] "polymer" refers more to a "polymer casing" (that is, the soft, external container) rather than a "polymer electrolyte". While the design is usually flat, and lightweight, it is not truly a polymer cell, since the electrolyte is still in liquid form, although it may be "plasticized" or "gelled" through a polymer additive.
LiFePO4
http://batteryuniversity.com/learn/article/types_of_lithium_ion
LMnO / LMO
http://batteryuniversity.com/learn/article/types_of_lithium_ion
high thermal stability and enhanced safety, but the cycle and calendar life are limited.
Low internal cell resistance enables fast charging and high-current discharging. In an 18650 package, Li-manganese can be discharged at currents of 20–30A with moderate heat buildup. It is also possible to apply one-second load pulses of up to 50A. A continuous high load at this current would cause heat buildup and the cell temperature cannot exceed 80°C. Li-manganese is used for power tools, medical instruments, as well as hybrid and electric vehicles.
Design flexibility allows engineers to maximize the battery for either optimal longevity (life span), maximum load current (specific power) or high capacity (specific energy). For example, the long-life version in the 18650 cell has a moderate capacity of only 1,100mAh; the high-capacity version is 1,500mAh.
Most Li-manganese batteries blend with lithium nickel manganese cobalt oxide (NMC) to improve the specific energy and prolong the life span. This combination brings out the best in each system, and the LMO (NMC) is chosen for most electric vehicles, such as the Nissan Leaf, Chevy Volt and BMW i3. The LMO part of the battery, which can be about 30 percent, provides high current boost on acceleration; the NMC part gives the long driving range.
| Lithium Manganese Oxide | |
| Voltages | 3.70V (3.80V) nominal; typical operating range 3.0–4.2V/cell |
| Specific energy (capacity) | 100–150Wh/kg |
| Charge (C-rate) | 0.7–1C typical, 3C maximum, charges to 4.20V (most cells) |
| Discharge (C-rate) | 1C; 10C possible with some cells, 30C pulse (5s), 2.50V cut-off |
| Cycle life | 300–700 (related to depth of discharge, temperature) |
| Thermal runaway | 250°C typical. High charge promotes thermal runaway |
| Applications | Power tools, medical devices, electric powertrains |
| Comments | High power but less capacity; safer than Li-cobalt; commonly mixed with NMC to improve performance. |
LiNiMnCoO2 / NMC
NCA et LTO
http://batteryuniversity.com/learn/article/types_of_lithium_ion
Sulphure de lithium
http://batteryuniversity.com/learn/article/types_of_lithium_ion
Modèles de location
Puisque c'est un modèle commercial qui est pratiqué (en particulier s'agissant de certains véhicules électriques), il vaudrait la peine de le décrire/comprendre afin d'en tenir compte et de ne pas passer à côté de solutions économiquement intéressantes.
