Patent Basics – USA

Definition: A patent is a set of exclusive rights granted by a state (national government) to an inventor or assignee for a limited period of time in exchange for public disclosure of an invention.

Purpose: Success of a patent application results in the government granting the creator or assignee monopoly control and explicit right to preclude others from making, using, selling or offering for sale the subject matter as defined by the patent claim(s) for some limited period of time. The monopoly incentive secures the assignees right to financial benefit, helping to enable a prosperous society.

Types: There are three types of patents within the United States Patent and Trademark Office USPTO that define the general nature of an invention.

Utility patents may be granted to anyone who invents or discovers any new and useful process, machine, article of manufacture, or composition of matter, or any new and useful improvement thereof;

Design patents may be granted to anyone who invents a new, original, and ornamental design for an article of manufacture; and

Plant patents may be granted to anyone who invents or discovers and asexually reproduces any distinct and new variety of plant.

Claim(s): The most important aspect of a patent is its claim. The claim relates the invention to its commercial application, or “art”, to which the patent pertains. This is where the value of a patent lies, and is the focal point of most legal proceedings. The claim illustrates the technical use and various embodiments of the invention by setting limits on the extent of protection conferred or sought by the patent.

Protection: The current patent term in the United States is 20 years which provides a sustainable competitive advantage to the assignee, usually a commercial enterprise or corporation, to directly or indirectly commercialize their invention for profit. The patent, in and of itself, provides no legal protection to a patent holder, protection only comes in the form of an infringement lawsuit filed by a patent holder against a patent infringer, making the defense of patents a rich mans game and not a simple process.

Process: In the United States, an inventor has a period of one year to file a provisional patent application from the date of first public disclosure, first public sale, or first public offer to sell an invention. A provisional application serves as a place holder within the USPTO for the eventual filing of a non-provisional application. The provisional application applies only to utility patents and can be as short or extensive as necessary to encompass the nature of the invention including drawings, data, and descriptions, but can be void of any claim(s), oaths, or information disclosure statements.

Once opened, a provisional application can be updated and expanded upon for a period of one year during which time a full non-provisional patent application must be filed in order to benefit from the earlier filing date and support provided by the provisional application. To be useful, the material contained in the provisional filing must adequately support as best as possible the subject matter of the claim(s) made in the non-provisional application. Once granted, the patent date will become the non-provisional application filing date.

Jurisdiction: For a small company with limited time and money, the largest and most fruitful market to apply for patent protection is the USA. Then depending on the nature of the invention, potential for profit, and further need for protection, additional applications can be made with other jurisdictions around the world as deemed necessary. Unfortunately there is no such thing as an international patent.

To be safe, all filings should be made as early as possible since most jurisdictions consider anything filed one year past any public disclosure makes the invention public domain, and voids any right for patent protection.

Cost: For a small entity, if done by oneself working directly with the USPTO, and preferably written by the inventor, filing for a patent is initially more of a time consuming process than a financial expense. For a small business, the cost to file a provisional patent is only US $110, plus the cost of a non-provisional patent which is US $165. After which, the bulk of the expense becomes the patent maintenance fees of US $490 due after 3.5 years, US $1,240 due after 7.5 years, and US $2,055 due after 11.5 years. All costs are double for non-small entities.

Lithium versus Lithium Ion – The difference is in the Anode

Metallic lithium rechargeable battery technology was first developed prior to 1970 and is still being pursued today by companies such as the Bolloré Group of France who recently acquired Avestor from Hydro Quebec in March of 2007 and Sion Power of Arizona with their Lithium Sulfur system. The defining aspect of lithium battery technology is that the anode itself is made of pure lithium metal in the form of a foil. During discharge, lithium ions dissolve from the surface of the foil and transfer to the cathode via the electrolyte. During charge, the lithium ions transfer back to the anode to be electroplated back onto the surface of the lithium foil, reforming as pure lithium metal once again, losing their status as “ions”.

Benefits of metallic lithium anodes are they are light weight and have high reversible capacity of 3,860 mAh/g. Problems are they are highly alkali in nature causing them to react with the organic electrolyte forming a passivation layer on their surface which leads to non-uniform plating of lithium during the charging process and formation of dendrites causing short circuits and serious safety problems due to localized hot spots. To overcome these problems, researchers in the 1970’s began studying the use of anode intercalation materials to replace metallic lithium. The new anode materials operate in the same fashion as existing cathode materials in that they hold the lithium atoms by insertion site diffusion, except that the anode materials do it at a much lower voltage closer to that of metallic lithium. Hence the lithium “ion” battery was born, where lithium atoms remain separate from one another at all times while residing in either the anode or cathode electrodes, eliminating the trouble of uneven metallic plating and its associated problems.

Lithium ion cells are termed rocking-chair cells because the lithium ions rock back and forth during charging and discharging between the anode and the cathode intercalation materials. Anode intercalation materials have much lower reversible capacities compared to metallic lithium, but the benefits of improved safety and much higher cycle life quickly outweigh the drawbacks in most applications.

The electrochemical potential of anode and cathode materials are measured relative to pure metallic lithium reference electrodes representing zero Volts, such that when a cell is constructed from an anode material with 0.3 Volts potential and a cathode material with 4.0 Volts potential, relative to metallic lithium, the resulting cell voltage is calculated by the difference, 4.0–0.3=3.7 Volts.

The most common anode material in use today is carbon in its layered form as graphite or in its glassy amorphous form as hard carbon. Carbon is cheap, light, environmentally friendly, has high reversible capacity of 372 mAh/g,  excellent cycling characteristics, and low electrochemical potential relative to metallic lithium in the range of 0.2-1.0 Volts, helping to maintain an overall high cell voltage when mated with other various cathode materials. Problems with carbon anodes are they are voluminous and have high irreversible first charge capacity loss in the range of 20%.

A less popular anode intercalation material is lithium titanate used by Toshiba and Altairnano, these metal oxide materials have low capacities of only 150 mAh/g and high electrochemical potentials of around 1.5 Volts resulting in a much lower energy density cell. Benefits are very good cycle life, stable electrolyte, and high power characteristics.

New silicon anode materials have very high theoretical capacities up to 4,200 mAh/g, exceeding that of even pure lithium, and voltage potentials below 1.0 Volts, but suffer from high mechanical stressing during the lithiation-delithiation processes, resulting in rapidly fading capacity loss during cycling. Other promising areas for new anode material developments include other silicides, nitrides, and lithium metal alloys.

Lithium Ion – Head and Shoulders Above The Rest

How much better? Let’s take a look.

There are four main rechargeable chemistries used today, lead acid, nickel cadmium, nickel metal hydride, and lithium ion, and conditions vary for how each is characterized in terms of capacity. Lead acid are tested using a C/20 discharge rate, while NiCd, NiMH, and lithium ion are all tested using a C/5 discharge rate. NiCd cells typically exceed their rated capacity by up to 10%, while NiMH often miss their rated capacity by up to 10%, and if we compress the discharge rate of lead acid testing from C/20 to C/5 making all things equal, we get a reduction in capacity of about 20%. So accounting for all these variations and adjustments, Table 1 roughly compares the chemistries on an even basis.

The lithium ion values represent a large format type manganese based cathode system similar to what are currently available from LG Chem and other manufacturers for electric vehicle applications.

Table 1

Chemistry Nominal Cell Voltage Capacity Ahr/kg C/5 discharge rate Energy Whr/kg C/5 discharge rate Life Cycles 100% DoD fade to 80% Energy Life-Cycle Product kWhr/kg
Sealed Lead Acid 2.0 12.5 25 500 13
Nickel Cadmium 1.2 31.6 38 700 27
Nickel Metal Hydride 1.2 53.3 64 500 32
Lithium Ion 3.7 39.2 145 2000 290

At present, lithium ion offers nearly an order of magnitude more, or 10 times the energy return over their lifetime than the next best chemistry NiMH, and nearly 25 times more than lead acid. Development work around the older chemistries is mainly complete now and stagnant, while development work around lithium ion technology is still young and fast paced, currently attracting thousands of scientist and researchers from around the world working toward yet to be discovered improvements and unlocking tremendous potential that still exists.

Practically, lithium ion energy density could be improved by a factor of 2-3 over the next 5-10 years, while cycle life improvement could also be doubled or quadrupled during the same period, resulting in an overall improvement by another factor of 5-10 from today.

As well as having superior “Energy Life-Cycle Product”, lithium ion cells have many other superior features that are both electrically and physically attractive in areas concerning discharge profile, charge-discharge efficiency, cost, manufacturing, environmental, and recycling.

Cell Basics, Anode, Cathode and Electrolyte Functions

Designation of the anode and cathode in a rechargeable cell are defined during the discharge process. The anode always refers to the negative electrode and the cathode always refers to the positive electrode, even though the reverse is actually true during charging, where the anode becomes the cathode and the cathode becomes the anode by definition of the terms anode and cathode. Common battery lingo maintains the anode cathode designations derived from the discharge process be applied when both discharging and charging in order to avoid confusion.

During discharge, the negative anode electrode is oxidized (loss of electrons is oxidation) and it is the source of electrons, while the positive cathode electrode is reduced (gain of electrons is reduction) and it is the receiver of electrons. Each electrode depends upon the other electrode to maintain a balance of flow of electrons. The number of electrons provided by the anode must equal the number of electrons received by the cathode.  Electrode materials are often described by their mAh/g capacity ratings, from which the amount of each material required for the construction of a balanced cell can be calculated.

During discharge, the number of electrons transferred in the external electric circuit from the anode to the cathode equals the number of ions (positive or negative atoms/molecules) that must be transferred by the cell’s internal electrolyte. The electrolyte is ionically conductive, but electronically non-conductive. The ionically conductive electrolyte completes the electro-chemical circuit by carrying only ions between the active cathode and anode materials. The electrode-electrolyte-electrode interfaces are where all the real action occurs within the cell, and these two interfaces determine much of the cells characteristics and features such as cell voltage, capacity, power capability, cycle life, calendar life, self discharge, temperature effects, safety, and more.

During charging, the anode and cathode reactions are reversed by forcing electrons to flow opposite in direction than they flowed during discharge. The charger must apply a voltage across the cells’ terminals that is higher in potential than the open circuit cell voltage in order to generate electron flow back into the anode from the cathode, electro-chemically reversing the chemical reaction that took place during the discharge phase. During charging the electrolyte must also reverse function and shuttle ions back from the cathode to the anode.

How to double the MPG of an SUV running on gasoline

Simple, build an SUV that runs on batteries and electric motors, then burn that same gasoline at more than double the efficiency of an ICE in a thermal power generating station to generate electricity to charge the batteries.

Internal combustion engines, or ICE powered vehicles, roll down the road plowing through the atmosphere by way of energy extracted from liquid fuels. Energy contained in liquid fuels is converted to mechanical energy by expansion of hot gases in an engine’s cylinders. The start of the power stroke converts the vaporized air-fuel mixture into extremely hot, high pressure carbon dioxide and water gases. The fuel’s state is transformed from a dense hydro-carbon chained liquid into individual species of hot CO2 and H2O gases via combustion with atmospheric oxygen.

Thermal efficiency of an ICE to deliver mechanical work from heat energy is roughly 20%, meaning that 80% of the heat energy contained in the fuel is wasted, blown out the tail pipe and radiator system. The problem with piston powered ICE vehicles is one of thermal dynamic inefficiency. Hot gases expanding in the cylinders during the power stroke cool and work is done as per Boyle’s law of gases. The expansion and cooling of hot combustion gases is how heat energy is physically converted to mechanical energy and waste heat, but because the temperature of the exhaust gases are still very high, with them goes a lot of unharnessed energy.

The solution to ICE inefficiency is simple, burn the fuel in a better method in order to extract more bang for your buck, and that better method is a thermal power generating station. A modern thermal electric power station can burn any type of fuel with a thermal efficiency as high as 48%, and when combined in a co-generating facility that uses an electric generator’s waste heat to supply nearby heating and absorptive cooling requirements, the overall efficiency of the fuel burned can be as high as 89%.

Consider also the additional energy expended during the extraction, refining, production, and delivery of gasoline and diesel fuels; a steam boiler system even when powered by coal starts to look pretty good. Large amounts of electrical energy are used by refineries during the refining processes to run pumps and provide heating. Fuel products are treated with hydrogen injection during cracking to produce lighter fuels from heavier oils. These extra energy inputs could be eliminated if the raw crude oil were simply burned directly in a co-gen facility producing combined electricity, heating, and cooling services.

When one drills down to the nuts and bolts of conventional gasoline and diesel fuels used for transportation, one finds that coal powered thermal generating stations are not really the devil they’re made out to be, and in fact, the real devil is in the extremely inefficient way our society uses oil products for transportation fuels and internal combustion engines.

Batteries… what’s the big deal?

It’s a huge deal and it’s about reversible energy storage. Energy is neither created nor destroyed, but can only change state. Energy is stored in batteries electro-chemically, as opposed to just chemically, as it is in fuels such as gasoline, oil, coal, natural gas, and even hydrogen. Energy stored in batteries is fundamentally different than traditional energy carriers by the fact that electro-chemical energy stored in secondary rechargeable batteries is a reversible process, whereas energy stored in fossil fuels is a non-reversible process.

Due to the shortcomings of fossil fuels not being able to reversibly store energy, we have labeled them “sources of energy” rather than “storage of energy”, and common parlance considers fossil fuels as energy sources, rather than energy carriers, which is in fact what they are. While batteries are correctly considered energy carriers, they have the added benefit of being extremely efficient and reversible.

Fossil fuels are nothing more than energy carriers that were charged millions of years ago by energy originating from the sun, trapped in plankton and other little creatures and plants for our use today. The drawback of fossil fuel energy systems is that they are not reversible. Energy released by burning hydro-carbon chains of any type is not a reversible process, once a fossil fuel has been burned to chemically extract its heat value through reaction with atmospheric oxygen to form the products of CO2 and H2O gas, the process is in no way reversible.

So, what’s the big deal about batteries? Simply put, they are incredible in their ability to easily, efficiently, and reversibly store energy. No other portable mechanism comes even close to their ability to effectively store and return large amounts of useful energy in a controlled and reversible manor. Battery energy storage and retrieval efficiency is typically between 85-95% for a complete charge-discharge cycle, meaning that for every 1000 Watt-hours of electrical power delivered to the battery of an electric scooter or electric car, that battery will return 850-950 Watt-hours of useful energy to drive the wheels, run the air conditioner, blow the heater, and play the radio… and that is quite a big deal from which future ramifications will be enormous.