High reliability lithium rechargeable batteries for specialties

Since their development in the late 1980s, lithium rechargeable batteries have enjoyed rapid growth and wide use as a commodity battery known for its higher energy density storage and lightweight convenience. These same attributes are emerging as a strong platform in power source development for the medical and aerospace sectors with highly customized applications and narrowly defined criteria. Accordingly, this new generation of lithium rechargeables must be hermetically sealed, have long-term storage capability, and zero-fault tolerances for common causes of field failures such as electrolyte leakage or short circuits from mechanical deformation. Quallion has been developing and manufacturing highly reliable lithium rechargeable cells for medical, aerospace, and specialty applications. Summarized in this paper are some key technologies developed at Quallion for designing and manufacturing of this new class of lithium rechargeable batteries. They include: 1) leakage reliability; 2) self-extinguishing electrolyte system; 3) mechanical impact resistance; 4) deep discharge storage; and 5) high reliability manufacturing.     

Electric propulsion: fleet readiness at affordable costs

The successful development and demonstration of the Al-AgO primary battery system dramatically demonstrated the viability of electric power plants for torpedo propulsion. Present efforts are focused on the development and demonstration of very low cost, quiet, high performance, safe, environmentally compatible, rechargeable batteries for heavyweight and lightweight torpedoes and tactical-sized UUVs. Electric power plants consisting of a rechargeable battery and a high reliability motor must be affordable to own and operate and enable turn-around without teardown for today's Fleet assets     

Performance characteristics of lithium-ion cells for NASA's Mars2001 Lander application

NASA requires lightweight rechargeable batteries for future missions to Mars and the outer planets that are capable of operating over a wide range of temperatures, with high specific energy and energy densities. Due to the attractive performance characteristics, lithium-ion batteries have been identified as the battery chemistry of choice for a number of future applications, including Mars rovers and landers. The Mars 2001 Lander (Mars Surveyor Program MSP 01) will be one of the first missions which will utilize lithium-ion technology. This application will require two lithium-ion batteries, each being 28 V (eight cells), 25 Ah and 8 kg. In addition to the requirement of being able to supply at least 200 cycles and 90 days of operation on the surface of Mars, the battery must be capable of operation (both charge and discharge) at temperatures as low as -20°C. To assess the viability of lithium-ion cells for these applications, a number of performance characterization tests have been performed, including: assessing the room temperature cycle life, low temperature cycle life (-20°C), rate capability as a function of temperature, pulse capability, self-discharge and storage characteristics, as well as mission profile capability. This paper describes the Mars 2001 Lander mission battery requirements and contains results of the cell testing conducted to-date in support of the mission,     

9th Annual Battery Conference on Advances and Applications

The developments in batteries reported at the 8th Annual Battery Conference on Advances and Applications, are discussed. It was sponsored by the electrical engineering department of California state university, long beach, CA, with IEEE-AESS cooperation. Previous well-funded battery research had been directed toward getting low weight in spacecraft batteries, which had to be boosted into orbit with expensive rockets. Ni-H₂ batteries, even though costly, won the race. Their demonstrated life, like 30,000 charge-discharge cycles, gives an earth-orbiting satellite decades of usable life. Other types of batteries discussed are: aircraft batteries; electric vehicle batteries; Ni-Cd cells; Zn-Br batteries; industrial Pb-acid batteries; rechargeability; computer controlled charging; and small rechargeable and primary batteries     

Global avionics in the future

The following topics are discussed: new batteries for old airplanes; new charge controls for lengthening battery life; fast methods for batteries charging; AC conductance measurement based battery testing; pulse power; bipolar lead-acid batteries vs supercapacitors; Ni electrode cells for spacecraft; worn-out battery disposal; recycling technology; vehicle batteries cost; high energy content batteries; and energy storage for electric utilities     

Segmented battery charger for high energy 28 V lithium ion battery

Since they were first introduced in the early 1990s, lithium ion batteries have enjoyed unprecedented growth and success in the consumer marketplace. Combining excellent performance with affordability, they have become the product of choice for portable computers and cellular phones. Building on the same energy and life cycle attributes, which marked their consumer market success, but adding new high power storage capability, lithium ion technology is now poised to play a similar role in the transportation, military, and space sectors. With major program in various aspects of electric and hybrid electric vehicles, Saft has developed a family of battery products that address the power and energy storage where lightweight, long life, and excellent energy or power storage capabilities are needed. Significant progress in the packaging and control of high power, yet compact, batteries has been accomplished for a variety of vehicle applications. This paper discusses the charger and balancing strategies of one of this family of products     

Portable power source needs of the future Army-batteries and fuelcells

This paper describes the US Army's future needs for silent portable power in the area of batteries and fuel cells. These needs will continue to increase as a result of the introduction of newer types of equipment, the increasing digitization of the battlefield, and future integrated Soldier Systems. Current battery programs are aimed at improved, low-cost primary batteries, and rechargeable batteries with increased energy densities. The Army fuel cell program aimed at portable systems capable of the order of 150 W is also described     

Thin-film Li-LiMn2O4 batteries

Thin-film rechargeable Li-LiMn₂O₄ batteries have been fabricated and characterized. Following deposition by electron beam evaporation of LiMn₂O₄, the amorphous as-deposited cathode films 1 cm² in area by 0.3to 4-μm thick were annealed at 700°C to 800°C in oxygen in order to form the crystalline spinet phase. The specific capacity of the cells between 4.5 V to 3.8 V ranged from 50 μAh/mg to 120 μAh/mg. When cycled over this range, the batteries exhibited excellent secondary performance with capacity losses as low as 0.001% per cycle. On charging to 5.3 V, a plateau with a median voltage of 5.1 V was observed. The total charge extracted between 3.8 V to 5.3 V corresponded to about 1 Li/Mn₂ O₄     

Advanced lithium ion battery charger

A lithium ion battery charger has been developed for four and eight cell batteries or multiples thereof. This charger has the advantage over those using commercial lithium ion charging chips in that the individual cells are allowed to be taper charged at their upper charging voltage rather than be cutoff when all cells of the string have reached the upper charging voltage limit. Since 30-60% of the capacity of lithium ion cells may be restored during the taper charge, this charger has a distinct benefit of fully charging lithium ion batteries by restoring all of the available capacity to all of its cells     

Charge equalization for series-connected batteries

A novel nondissipative charge equalization circuit is proposed for charge equalization control of series-connected batteries. Each battery associates with a subcircuit, which is essentially a buck-boost converter acting as a current diverter to redistribute the excessive energy from more affluent batteries to the hungry ones. By dynamically redistributing the charging current, charge equalization can be achieved more quickly and efficiently. The applicability of this approach is confirmed by experiments.     

The Hy-StorTM battery

The Hy-Stor^TM Battery is a rechargeable battery being developed for electric vehicles and other large battery applications. The battery combines the high energy storage capability of metal hydride alloys with the high cycle life and discharge rate capabilities of nickel-hydrogen cells. It is a hybrid battery concept that offers potential performance, economic and safety advantages over other large battery technologies. Very recent developments indicate that much smaller batteries can also be produced to meet the needs of the portable computer and other portable electronic device markets. Initial tests demonstrated the ability of a metal hydride storage system to achieve high cycle life when absorbing hydrogen that was saturated with battery electrolyte solution and then passed through a purifier. Based on positive test results, a patent for the Hy-Stor battery was applied for and granted     

新能源电动飞机发展与挑战

发展绿色航空是人类社会形成的基本共识,新能源电动飞机为实现彻底的绿色航空提供了一条光明的技术途径。简述了航空对环境的影响、电在飞机上的应用及电动飞机的发展历程,对新能源电动飞机的能源分类、电推进系统及其总体效率进行了研究,重点针对载人轻型运动飞机,分析了电动飞机的发展现状、特征以及能源需求,通过对电池作为能源的载人电动飞机的航程和极限航程研究,提出了电池能量密度提升和性能改进、高升阻比空气动力设计、低成本轻质高效复合材料结构设计与制造、高效率电推进系统设计与集成等电动飞机发展面临的挑战,给出了应大力发展电动飞机的建议和本领域未来的研究方向。     

Hubble Space Telescope at twelve years of age

The Hubble Space Telescope was deployed from the Space Shuttle Discovery into a 380-mile high Earth orbit on April 25, 1990. It subsequently made outstanding astronomical discoveries with its 8-foot (2.4-meter) telescope and other scientific instruments. Critical to the successful observations was continuous availability of power from its solar arrays during sunlit periods, and from nickel-hydrogen batteries when the satellite was in the Earth's shadow. The adopted nickel-hydrogen batteries were carefully selected and tested to confirm their depth-of-discharge and operating temperature that delivered the longest life in charge/discharge cycling service. These batteries had a design life of 7 years. At 12 years after launch the Hubble batteries have delivered more charge/discharge cycles than any other batteries in low-Earth orbit. However, the Hubble batteries have been subjected to many unexpected stresses, and peculiar reductions in battery capacity have been observed. Battery replacement requires a costly trip to the Hubble Space Telescope by astronauts, so the remaining useful life of the batteries must be predicted. Already in four servicing missions, astronauts have replaced or modified optics, solar arrays, a power control unit, and various science packages. A fifth servicing mission is scheduled in 2004. This paper discusses battery charging hardware and software controls, history of battery events in Hubble, cell performance model and spare battery tests, and capacity walkdown.     

Power sources and portable computers

The safety aspects of the nickel-metal-hydride and high-capacity nickel-cadmium batteries used in Apple Computer's current notebook computers are discussed. No problems are anticipated with nickel-cadmium packs, which have an excellent record for safety because the cell design parameters are well understood and there is ample safety margin under abusive conditions. At its early stage of development, the nickel-metal-hydride cell is not as electrochemically robust as the nickel-cadmium, and it does not have as wide an operational temperature range. The possible hydrogen release from nickel-metal-hydride batteries on charging at low temperatures can also be a potential explosion hazard. Nickel-metal-hydride is considered less environmentally harmful than nickel-cadmium and has escaped legislated recycling requirements     

U.S. Army battery needs-present and future

The purpose of this paper is to describe the needs of the U.S. Army for silent portable power sources, both in the near and longer term future. As a means of doing this, the programs of the Power Sources Division of the Army Research Laboratory are discussed. In carrying out these programs, the personnel of the Power Sources Division work closely with the Battery Management Office of the Army Materiel Command, which is located in the Logistics and Readiness Directorate of the Communication-Electronics Command (CECOM). We are also closely integrated with the Army Research Office, and the fuel cell personnel of the CECOM Research Development and Engineering Center (RDEC), and the battery personnel of the RDECs for the Tank and Automotive Command and the Missile Command. The six program areas discussed in which the Power Sources Division is engaged are: primary batteries, rechargeable batteries, reserve/fuze batteries, pulse batteries and capacitors, fuel cells, and thermophotovoltaic power generation     

Charging the new batteries-IC controllers track new technologies

Demands for portability have fueled significant developments in new battery technology. These developments have resulted in many more options in selecting the battery type for use in a particular project, but since most applications today are opting for rechargeable battery systems, the availability of battery charging solutions can become an equally important criteria in the selection process. Complicating this process are the demands for fast-but safe-charging with charge algorithms easily implemented with low-cost hardware. With the higher levels of complexity attendant with these more demanding algorithms, solutions have come primarily from the integrated circuit industry and the purpose of this paper is to provide a few examples of the latest efforts in this arena, specifically as addressed to lead-acid, nickel metal-hydride, and lithium-ion technologies     

A microcontroller-based intelligent battery system

State-of-charge indication for a secondary battery is becoming increasingly important for battery-operated electronics. Consumers are demanding fast charging times, increased battery lifetime, and fuel gauge capabilities. All of these demands require that the state of charge within a battery be known. One of the simplest methods employed to determine state of charge is to monitor the voltage of the battery. However, this method alone is not a good indicator of battery energy, since both NiMH and NiCd batteries have voltage-versus-energy curves that are essentially flat. This paper presents a more effective method of determining the state of charge in secondary cell batteries. A NiMH battery is used as our test vehicle, since it is one of the more difficult batteries to determine state of charge. This method monitors the battery's temperature, voltage, and discharge/charge rate. A microcontroller then manipulates the information, using look-up tables to determine the state of charge. Also, by modifying the look-up tables, this technique can be employed in many other battery technologies and is not limited to NiMH     

电池条形码综合管理系统设计与开发

从目前小型二次电池生产和应用的现状出发,结合条形码管理的实际特点,介绍了一种新型的电池条形码综合管理系统.系统通过在电池生产过程中引入条形码管理技术,便于电池生产厂家控制生产过程中电池质量、电池Pack厂在组装电池组时提取过程数据及电池流入市场后问题电池的追踪.详细介绍了系统的软硬件结构设计及系统特点,并对系统发展提出展望.     

Lithium-ion battery software safety protection

Production Li-ion batteries include hardware and software safety protection. The hardware protection includes PTC (positive temperature coefficient) thermistor switch, electrical circuit disconnect and rupture vent. The software protection involves a charging algorithm (charging to ultimate voltage), which is used with internal electrical circuitry (cell voltage control and equalization circuit). This paper discusses a specific charging algorithm and additional software protection features associated with hard, soft and chemical shunt recognition