Six things to pay attention to when using smartphone batteries

The evolution of the smartphone market has always revolved around one question: How to comfortably access consumers' favorite apps and services?

No smartphone manufacturer can give a satisfactory answer, because all manufacturers face a dilemma: higher performance electronic products, faster data transmission speeds, better quality videos and games, more vivid and exquisite displays, all of which have been developing at the speed of Moore's Law, but the batteries used cannot keep up with the demand. It has become an indisputable fact that smartphone users complain about the short battery life.

The tension between functionality and battery life is the best explanation for why the new iPad is thicker and heavier than the old one. To accommodate the needs of the Retina display, 4G LTE network, graphics processing improvements, etc., the battery size and weight need to be increased by 70%. Even so, the battery life of the new iPad is still not as good as that of the iPad 2.

Smartphone manufacturers have been limited in their designs by lithium-ion batteries . If you want to know what features will be available on the future iPhone 5, Android devices, or Windows Phones, here are six things you need to know about smartphone batteries:

1. Sealed battery packaging

Lithium-ion batteries are sealed packages containing layered anode and cathode plates separated by a separator, with a liquid electrolyte permeating between the layers. Tablet batteries are usually made up of multiple cells, and the new iPad battery has three cells, but smartphones are usually powered by a single battery. At one end of the battery, a printed circuit board connects the positive and negative terminals of each battery and provides short-circuit protection, overcharge protection, and forced discharge protection. Lithium-ion batteries are fragile and require smartphone cases to protect them, so they cannot be replaced by users.

2. Battery life

Lithium-ion battery energy density determines how long a user can run with a battery of a given size and weight. Lithium-ion battery technology was introduced to the market in 1991. Since then, processors have had more than 1,000 times more transistors, but lithium-ion energy density has only tripled. The density of electronic components has made a lot of cool features possible, but it requires more energy consumption. Unfortunately, battery manufacturers have been slow to improve energy density. This is why non-replaceable lithium-ion batteries are favored by smartphone and tablet designers. Without a protective case to keep the battery safe, sealed lithium-ion batteries would be thinner and provide longer battery life.

3. Battery volume and energy density are inseparable

Energy density is affected by the ratio of the thickness of a sealed lithium-ion battery to its width (X) and length (Y). Energy density decreases as the sealed package becomes thinner. When a printed circuit board is mounted on one end of a short, narrow battery, there is no more room for the active material to store energy. A narrow, thick battery has a higher energy density for the same volume.

4. The necessity of keeping the battery cool

Sealed lithium-ion batteries can’t get too hot. Standard lithium-ion chemistry depends on the electrolyte reacting with excess water to produce hydrofluoric acid, the most corrosive of all compounds. As with all chemical reactions, the rate of the reaction doubles with every 10 degrees Celsius increase in temperature, resulting in a reduction in battery life and cycle life: not only does the runtime drop on a single charge, but each charge and discharge cycle also reduces it further, until it becomes unusable without a recharge. Worse still, lithium-ion batteries themselves generate heat during charging and discharging: the more power your smartphone demands or the faster it charges, the hotter the battery gets.

5. Create a smartphone

Motorola's Droid Razr smartphone has a three-layer design: display, circuit board and battery. The iPhone 4 has a two-layer design: display and electronics: the printed circuit board makes room for the battery. In either case, a large display means more room for the battery. Although narrow and thick batteries have higher energy density, the three-layer design makes it difficult to protect the battery from the heat of the components, which shortens the battery life.

6. Chemical reaction process: packaging trump card

Improvements in lithium-ion chemical reaction processes may significantly improve energy density, providing smartphone designers with more options in the conflict between functionality and battery life. Currently, major breakthroughs have been made in active material research, and some new solutions have entered the market. One of the new solutions is to use a new lithium imide electrolyte that does not produce hydrofluoric acid, significantly improves battery heat resistance and battery life, and makes the battery thinner by eliminating the current lithium-ion battery seal thickness.

Bottom Line

Until new advances are made in lithium-ion sealed batteries, it is not expected that Apple or other smartphone manufacturers will make major changes in design. It will take at least 12-18 months for new breakthroughs to be possible. New active materials and new electrolytes will increase the battery life of the same size by 20% per charge. This type of battery will provide Apple iPhone 6 with more options, allowing it to configure faster processors, more energy-intensive displays and more applications without sacrificing battery life, and allowing iPhone 6 to continue to maintain its thin and beautiful appearance.