Naraščajoče povpraševanje po manjši, lažji in zmogljivejši prenosni elektroniki je odvisno od napredka v Litij-ionska (li-ionska) baterija tehnologija. Oblikovanje baterijskih sklopov za sodobne naprave zahteva uravnoteženje gostote energije, varnosti, velikosti, teže, stroškov in skladnosti z zakonodajo.
Omejitve velikosti in teže baterije
Večji paketi baterij običajno oddajajo večji tok za daljša obdobja.
Vendar pa se prenosne naprave soočajo z omejitvami teže in prostora, zaradi česar morajo proizvajalci oblikovati lahke pakete, ki še vedno zagotavljajo znatno moč.
Litij-ionske baterije so na voljo v različnih oblikah za te naprave, vključno z cilindrični, prizmatičniin vrečke iz polimernih celic.
Cilindrične celice (npr. 18650, 26650, 21700)
Cilindrične celice imajo zrelo proizvodnjo, visoko specifično energijo (200-260 Wh/kg), odlično toplotno upravljanje in stroškovno učinkovitost. Toda njihova toga oblika omejuje volumetrično gostoto energije (500–600 Wh/L) in prilagodljivost zasnove.
Integracija več celic doda kompleksnost in neučinkovit prostor. Običajno se uporabljajo v prenosnih medicinskih napravah, ročnih komercialnih in vojaških orodjih ter električnih orodjih.
Prizmatične celice
Prizmatične celice imajo pravokotno ohišje in običajno ponujajo višjo volumetrično gostoto energije (600-700 Wh/L) kot cilindrične celice zaradi boljše izkoriščenosti prostora.
Imajo vmesno konstrukcijsko prilagodljivost, vendar imajo lahko nekoliko nižjo specifično energijo (160–220 Wh/kg) in višjo ceno na kWh. Tudi termično upravljanje je lahko zahtevnejše.
Polimerne celice (vrečaste celice)
Polymer cells have flexible aluminum laminate casings and high volumetric energy density (600-800 Wh/L), making them suitable for thin or irregular shapes.
They offer a good weight-to-capacity ratio (250-300 Wh/kg) but lack mechanical rigidity, needing strong structural support.
Challenges include thermal management and manufacturing costs. These cells are often used in portable devices like wearables, medical equipment, drones, laptops, and tablets.
Watt Hour Limitations
A key design parameter is total energy capacity, measured in Watt-hours (Wh = Voltage * Amp-hours). Increasing Wh extends runtime but also increases size, weight, and cost.
Safety regulations impose strict limits on Wh for air travel: Cells under 20 Wh and baterijski paketi under 100 Wh are allowed without restrictions.
Packs between 100-160 Wh require airline approval, with a maximum of two per passenger or spares. Packs over 160 Wh are typically banned as carry-on. These regulations significantly impact the maximum energy available for high-performance ultraportables like premium laptops.
Charging Design Options
Charging lithium-ion batteries requires specific parameters.
Unlike other batteries, they need dedicated chargers due to manufacturer design variations affecting current and voltage settings.
With lower resistance, lithium-ion cells enable faster charging, so chargers must deliver the correct current without overcharging or undercharging. Custom chargers for specific battery packs are preferred over off-the-shelf models.
BMS Designs
Battery management systems (BMS) protect lithium-ion batteries from issues like high temperatures, overcharging, undercharging, and toplotni beg. Regulations mandate BMS installation for all baterije na osnovi litija, including portable devices.
For portables, BMS features include temperature monitoring, overcharging and discharging management, and fault diagnosis.
Interoperability is also essential for communicating battery condition across networks and controller systems.
Enclosure Special Features
Safety is crucial for portable devices using lithium-ion batteries. These batteries must be protected from punctures and damage if the device is dropped or mishandled.
Circuit protection, like polymeric positive temperature coefficient (PPTC) devices, can safeguard circuits during shipping and transport.
Enclosures also protect lithium-ion batteries from shocks and vibrations while allowing gas venting and heat dissipation.
Manufacturers offer various enclosure options, including shrink wrap, vacuum-formed plastic, and injection-molded plastic, which undergo safety drop testing to ensure durability and reliability.
Portability Regulations
Transportation regulations for lithium-ion batteries apply to both portable and non-portable devices.
All lithium batteries must include BMS components, whether shipped separately or installed. They are limited to a maximum of 100 watt-hours unless approved by the carrier. Portable devices require safety testing and certification.
Starting January 2026, lithium-ion batteries shipped alone must have a state of charge (SoC) of 30% or less. Additionally, packaging for non-specification shipping must meet the 3. 0 meter stack test if containing batteries within or packed with devices.
Zaključek
Designing lithium-ion battery packs for portable devices depends on the device’s needs, industry standards (such as those for medical or military use), and necessary regulations. A Proizvajalec baterij po meri like Holo Battery can help determine the right technology and features to ensure your battery pack functions effectively, remains reliable, and is safe.
